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Sample records for fagus sylvatica fspp2c1

  1. Negative Regulation of Abscisic Acid Signaling by the Fagus sylvatica FsPP2C1 Plays A Role in Seed Dormancy Regulation and Promotion of Seed Germination1

    PubMed Central

    González-García, Mary Paz; Rodríguez, Dolores; Nicolás, Carlos; Rodríguez, Pedro Luis; Nicolás, Gregorio; Lorenzo, Oscar

    2003-01-01

    FsPP2C1 was previously isolated from beech (Fagus sylvatica) seeds as a functional protein phosphatase type-2C (PP2C) with all the conserved features of these enzymes and high homology to ABI1, ABI2, and PP2CA, PP2Cs identified as negative regulators of ABA signaling. The expression of FsPP2C1 was induced upon abscisic acid (ABA) treatment and was also up-regulated during early weeks of stratification. Furthermore, this gene was specifically expressed in ABA-treated seeds and was hardly detectable in vegetative tissues. In this report, to provide genetic evidence on FsPP2C1 function in seed dormancy and germination, we used an overexpression approach in Arabidopsis because transgenic work is not feasible in beech. Constitutive expression of FsPP2C1 under the cauliflower mosaic virus 35S promoter confers ABA insensitivity in Arabidopsis seeds and, consequently, a reduced degree of seed dormancy. Additionally, transgenic 35S:FsPP2C1 plants are able to germinate under unfavorable conditions, as inhibitory concentrations of mannitol, NaCl, or paclobutrazol. In vegetative tissues, Arabidopsis FsPP2C1 transgenic plants show ABA-resistant early root growth and diminished induction of the ABA-response genes RAB18 and KIN2, but no effect on stomatal closure regulation. Seed and vegetative phenotypes of Arabidopsis 35S:FsPP2C1 plants suggest that FsPP2C1 negatively regulates ABA signaling. The ABA inducibility of FsPP2C1 expression, together with the transcript accumulation mainly in seeds, suggest that it could play an important role modulating ABA signaling in beechnuts through a negative feedback loop. Finally, we suggest that negative regulation of ABA signaling by FsPP2C1 is a factor contributing to promote the transition from seed dormancy to germination during early weeks of stratification. PMID:12970481

  2. The Nuclear Interactor PYL8/RCAR3 of Fagus sylvatica FsPP2C1 Is a Positive Regulator of Abscisic Acid Signaling in Seeds and Stress1[C][W][OA

    PubMed Central

    Saavedra, Xandra; Modrego, Abelardo; Rodríguez, Dolores; González-García, Mary Paz; Sanz, Luis; Nicolás, Gregorio; Lorenzo, Oscar

    2010-01-01

    The functional protein phosphatase type 2C from beechnut (Fagus sylvatica; FsPP2C1) was a negative regulator of abscisic acid (ABA) signaling in seeds. In this report, to get deeper insight on FsPP2C1 function, we aim to identify PP2C-interacting partners. Two closely related members (PYL8/RCAR3 and PYL7/RCAR2) of the Arabidopsis (Arabidopsis thaliana) BetV I family were shown to bind FsPP2C1 in a yeast two-hybrid screening and in an ABA-independent manner. By transient expression of FsPP2C1 and PYL8/RCAR3 in epidermal onion (Allium cepa) cells and agroinfiltration in tobacco (Nicotiana benthamiana) as green fluorescent protein fusion proteins, we obtained evidence supporting the subcellular localization of both proteins mainly in the nucleus and in both the cytosol and the nucleus, respectively. The in planta interaction of both proteins in tobacco cells by bimolecular fluorescence complementation assays resulted in a specific nuclear colocalization of this interaction. Constitutive overexpression of PYL8/RCAR3 confers ABA hypersensitivity in Arabidopsis seeds and, consequently, an enhanced degree of seed dormancy. Additionally, transgenic 35S:PYL8/RCAR3 plants are unable to germinate under low concentrations of mannitol, NaCl, or paclobutrazol, which are not inhibiting conditions to the wild type. In vegetative tissues, Arabidopsis PYL8/RCAR3 transgenic plants show ABA-resistant drought response and a strong inhibition of early root growth. These phenotypes are strengthened at the molecular level with the enhanced induction of several ABA response genes. Both seed and vegetative phenotypes of Arabidopsis 35S:PYL8/RCAR3 plants are opposite those of 35S:FsPP2C1 plants. Finally, double transgenic plants confirm the role of PYL8/RCAR3 by antagonizing FsPP2C1 function and demonstrating that PYL8/RCAR3 positively regulates ABA signaling during germination and abiotic stress responses. PMID:19889877

  3. A New Protein Phosphatase 2C (FsPP2C1) Induced by Abscisic Acid Is Specifically Expressed in Dormant Beechnut Seeds1

    PubMed Central

    Lorenzo, Oscar; Rodríguez, Dolores; Nicolás, Gregorio; Rodríguez, Pedro L.; Nicolás, Carlos

    2001-01-01

    An abscisic acid (ABA)-induced cDNA fragment encoding a putative protein phosphatase 2C (PP2C) was obtained by means of differential reverse transcriptase-polymerase chain reaction approach. The full-length clone was isolated from a cDNA library constructed using mRNA from ABA-treated beechnut (Fagus sylvatica) seeds. This clone presents all the features of plant type PP2C and exhibits homology to members of this family such as AthPP2CA (61%), ABI1 (48%), or ABI2 (47%), therefore it was named FsPP2C1. The expression of FsPP2C1 is detected in dormant seeds and increases after ABA treatment, when seeds are maintained dormant, but it decreases and tends to disappear when dormancy is being released by stratification or under gibberellic acid treatment. Moreover, drought stress seems to have no effect on FsPP2C1 transcript accumulation. The FsPP2C1 transcript expression is tissue specific and was found to accumulate in ABA-treated seeds rather than in other ABA-treated vegetative tissues examined. These results suggest that the corresponding protein could be related to ABA-induced seed dormancy. By expressing FsPP2C1 in Escherichia coli as a histidine tag fusion protein, we have obtained direct biochemical evidence supporting Mg2+-dependent phosphatase activity of this protein. PMID:11299374

  4. Do variations in leaf phenology affect radial growth variations in Fagus sylvatica?

    NASA Astrophysics Data System (ADS)

    Čufar, Katarina; De Luis, Martin; Prislan, Peter; Gričar, Jožica; Črepinšek, Zalika; Merela, Maks; Kajfež-Bogataj, Lučka

    2015-08-01

    We used a dendrochronological and leaf phenology network of European beech ( Fagus sylvatica) in Slovenia, a transitional area between Mediterranean, Alpine and continental climatic regimes, for the period 1955-2007 to test whether year to year variations in leaf unfolding and canopy duration (i.e. time between leaf unfolding and colouring) influence radial growth (annual xylem production and tree ring widths) and if such influences are more pronounced at higher altitudes. We showed that variability in leaf phenology has no significant effect on variations in radial growth. The results are consistent in the entire region, irrespective of the climatic regime or altitude, although previous studies have shown that leaf phenology and tree ring variation depend on altitude. The lack of relationship between year to year variability in leaf phenology and radial growth may suggest that earlier leaf unfolding—as observed in a previous study—probably does not cause increased tree growth rates in beech in Slovenia.

  5. The cough suppressive activity of sulfated glucuronoxylan from Fagus sylvatica L.

    PubMed

    Nosáľova, G; Jureček, L; Turjan, J; Capek, P; Prisenžňáková, L; Fraňová, S

    2014-06-01

    Hemicellulose polysaccharides represent a large group of natural renewable polymers, however, their application potency is still low. In our study a hardwood 4-O-methylglucuronoxylan was isolated by alkali peroxide extraction of Fagus sylvatica sawdust and modified into sulfated water soluble derivative (MGXS). Highly sulfated MGXS was characterized by HPLC, FTIR and NMR spectroscopies, and tested in vivo on chemically induced cough reflex and smooth muscles reactivity. Farmacological tests revealed an interesting antitussive activity of MGXS. Comparative tests with drug commonly used in a clinical practice revealed that antitussive activity of MGXS was lower than that of opioid receptor agonist codeine, the strongest antitussive drug. Furthermore, the specific reactivity of airways smooth muscle was not significantly affected by MGXS, indicating thus that the polymer is not involved in the bronchodilation process.

  6. Do variations in leaf phenology affect radial growth variations in Fagus sylvatica?

    PubMed

    Čufar, Katarina; De Luis, Martin; Prislan, Peter; Gričar, Jožica; Črepinšek, Zalika; Merela, Maks; Kajfež-Bogataj, Lučka

    2015-08-01

    We used a dendrochronological and leaf phenology network of European beech (Fagus sylvatica) in Slovenia, a transitional area between Mediterranean, Alpine and continental climatic regimes, for the period 1955-2007 to test whether year to year variations in leaf unfolding and canopy duration (i.e. time between leaf unfolding and colouring) influence radial growth (annual xylem production and tree ring widths) and if such influences are more pronounced at higher altitudes. We showed that variability in leaf phenology has no significant effect on variations in radial growth. The results are consistent in the entire region, irrespective of the climatic regime or altitude, although previous studies have shown that leaf phenology and tree ring variation depend on altitude. The lack of relationship between year to year variability in leaf phenology and radial growth may suggest that earlier leaf unfolding--as observed in a previous study--probably does not cause increased tree growth rates in beech in Slovenia.

  7. Leaf litter decomposition in temperate deciduous forest stands with a decreasing fraction of beech (Fagus sylvatica).

    PubMed

    Jacob, Mascha; Viedenz, Karin; Polle, Andrea; Thomas, Frank M

    2010-12-01

    We hypothesised that the decomposition rates of leaf litter will increase along a gradient of decreasing fraction of the European beech (Fagus sylvatica) and increasing tree species diversity in the generally beech-dominated Central European temperate deciduous forests due to an increase in litter quality. We studied the decomposition of leaf litter including its lignin fraction in monospecific (pure beech) stands and in stands with up to five tree genera (Acer spp., Carpinus betulus, Fagus sylvatica, Fraxinus excelsior, Tilia spp.) using a litterbag approach. Litter and lignin decomposition was more rapid in stand-representative litter from multispecific stands than in litter from pure beech stands. Except for beech litter, the decomposition rates of species-specific tree litter did not differ significantly among the stand types, but were most rapid in Fraxinus excelsior and slowest in beech in an interspecific comparison. Pairwise comparisons of the decomposition of beech litter with litter of the other tree species (except for Acer platanoides) revealed a "home field advantage" of up to 20% (more rapid litter decomposition in stands with a high fraction of its own species than in stands with a different tree species composition). Decomposition of stand-representative litter mixtures displayed additive characteristics, not significantly more rapid than predicted by the decomposition of litter from the individual tree species. Leaf litter decomposition rates were positively correlated with the initial N and Ca concentrations of the litter, and negatively with the initial C:N, C:P and lignin:N ratios. The results support our hypothesis that the overall decomposition rates are mainly influenced by the chemical composition of the individual litter species. Thus, the fraction of individual tree species in the species composition seems to be more important for the litter decomposition rates than tree species diversity itself.

  8. Drought-Adaptation Potential in Fagus sylvatica: Linking Moisture Availability with Genetic Diversity and Dendrochronology

    PubMed Central

    Pluess, Andrea R.; Weber, Pascale

    2012-01-01

    Background Microevolution is essential for species persistence especially under anticipated climate change scenarios. Species distribution projection models suggested that the dominant tree species of lowland forests in Switzerland, European beech (Fagus sylvatica L.), might disappear from most areas due to expected longer dry periods. However, if genotypes at the moisture boundary of the species climatic envelope are adapted to lower moisture availability, they can serve as seed source for the continuation of beech forests under changing climates. Methodology/Principal Findings With an AFLP genome scan approach, we studied neutral and potentially adaptive genetic variation in Fagus sylvatica in three regions containing a dry and a mesic site each (nind. = 241, nmarkers = 517). We linked this dataset with dendrochronological growth measures and local moisture availabilities based on precipitation and soil characteristics. Genetic diversity decreased slightly at dry sites. Overall genetic differentiation was low (Fst = 0.028) and Bayesian cluster analysis grouped all populations together suggesting high (historical) gene flow. The Bayesian outlier analyses indicated 13 markers with three markers differing between all dry and mesic sites and the others between the contrasting sites within individual regions. A total of 41 markers, including seven outlier loci, changed their frequency with local moisture availability. Tree height and median basal growth increments were reduced at dry sites, but marker presence/absence was not related to dendrochronological characteristics. Conclusion and Their Significance The outlier alleles and the makers with changing frequencies in relation to moisture availability indicate microevolutionary processes occurring within short geographic distances. The general genetic similarity among sites suggests that ‘preadaptive’ genes can easily spread across the landscape. Yet, due to the long live span of trees, fostering

  9. Variation in biogenic volatile organic compound emission pattern of Fagus sylvatica L. due to aphid infection

    NASA Astrophysics Data System (ADS)

    Joó, É.; Van Langenhove, H.; Šimpraga, M.; Steppe, K.; Amelynck, C.; Schoon, N.; Müller, J.-F.; Dewulf, J.

    2010-01-01

    Volatile organic compounds (VOCs) have been the focus of interest to understand atmospheric processes and their consequences in formation of ozone or aerosol particles; therefore, VOCs contribute to climate change. In this study, biogenic VOCs (BVOCs) emitted from Fagus sylvatica L. trees were measured in a dynamic enclosure system. In total 18 compounds were identified: 11 monoterpenes (MT), an oxygenated MT, a homoterpene (C 14H 18), 3 sesquiterpenes (SQT), isoprene and methyl salicylate. The frequency distribution of the compounds was tested to determine a relation with the presence of the aphid Phyllaphis fagi L. It was found that linalool, (E)-β-ocimene, α-farnesene and a homoterpene identified as (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), were present in significantly more samples when infection was present on the trees. The observed emission spectrum from F. sylvatica L. shifted from MT to linalool, α-farnesene, (E)-β-ocimene and DMNT due to the aphid infection. Sabinene was quantitatively the most prevalent compound in both, non-infected and infected samples. In the presence of aphids α-farnesene and linalool became the second and third most important BVOC emitted. According to our investigation, the emission fingerprint is expected to be more complex than commonly presumed.

  10. Long-range transport of beech ( Fagus sylvatica L.) pollen to Catalonia (north-eastern Spain)

    NASA Astrophysics Data System (ADS)

    Belmonte, J.; Alarcón, M.; Avila, A.; Scialabba, E.; Pino, D.

    2008-09-01

    Local and long-range transport of beech ( Fagus sylvatica) pollen was analysed by using 23-year data (1983-2007) at six stations in Catalonia, Spain, and numerical simulations. Back trajectories and synoptic meteorology indicated a consistent north European provenance during beech pollen peak days. Specifically, the area from northern Italy to central Germany was the most probable source, as indicated by a source-receptor model based on back trajectories. For the event with the highest pollen levels (17 May 2004), back trajectories indicated a source in the Vosges (NE France) and the Schwarzwald (SW Germany) regions. By applying a mesoscale model (MM5) to this event, pollen transport could be further refined, allowing its entrance to Catalonia through the lower easternmost pass of the Pyrenees (the Alberes pass, 500 m a.s.l.) to be described. Hourly counts of Fagus pollen allowed the timing of pollen arrival during this episode to be matched with the model results regarding the above-mentioned passage. This study may help to interpret some results of modern beech genetic diversity and contribute to the understanding of paleopalynological records by taking long-range transport into consideration.

  11. Fast wood decay in a mountain Mediterranean area having Fagus sylvatica forests

    NASA Astrophysics Data System (ADS)

    Fravolini, Giulia; Egli, Markus; Cherubini, Paolo; Tognetti, Roberto; Lombardi, Fabio; Marchetti, Marco

    2015-04-01

    Deadwood and litter act as important linkages between recent productivity and current community, and ecosystem processes. The increasing interest in the quantity and properties of coarse woody debris (CWD) and litter is relevant both to maintaining biodiversity and to global C dynamics. Mountain and Mediterranean areas, furthermore, are considered to be especially sensitive to changing environmental conditions. Consequently, a need exists to understand more in detail the interplay between soils, forests, deadwood and climate in general and in particular in mountain Mediterranean areas such as the Appenine. Due to the fact that linkages between climate, coarse woody decay and soils in mountain Mediterranean areas are only poorly understood, we aimed at investigating the decay mechanism of Fagus silvatica as a function of altitude and exposure. Furthermore, the effects of exposure on the decay dynamics of dead wood and soils were compared along a altitudinal sequence in an Appenine mountain forest (Majella Mountain). Ten sites, five of which having north and the other 5 having south exposure, were investigated, ranging from 1000 m to 1650 m asl. All sites have a Fagus sylvatica forest. In addition to this, experimental plots were installed at each site. In May 2014 standardised wood blocks (5 x 5 x 2 cm) of local Fagus sylvatica were placed at each site inside PVC tubes ('mesocosms') that was filled with undisturbed soil material. The sampling design foresees that three replicates of such mesocosms per site will be sampled after 8 , 16, 52 and 104 weeks. After 8 weeks three tubes were removed from the sites (sampled soil and dead wood blocks) and the wood blocks analysed for cellulose, lignin and density. At each site, three cores were taken to analyse soil properties. The soil cores were subdivided in 0 - 5, 5 - 10 and 10 - 15 cm depth and measured for organic carbon, carbonates and pH. In addition, the humus forms at each site were determined. Already after 8 weeks

  12. Branch enclosure BVOC flux measurements from Fagus sylvatica L. in a natural forest environment: preliminary results

    NASA Astrophysics Data System (ADS)

    Demarcke, M.; Amelynck, C.; Schoon, N.; Müller, J.-F.; Joo, E.; Dewulf, J.; van Langenhove, H.; Šimpraga, M.; Steppe, K.; Lemeur, R.; Samson, R.

    2009-04-01

    Natural ecosystems, such as forests, are known to be important sources of non-methane volatile organic compounds (NMVOCs). Oxidation of these biogenic VOCs (BVOCs) in the presence of nitrogen oxides can result in net ozone formation and the low-volatility oxidation products may contribute to secondary organic aerosol formation and/or growth. As a result BVOC emissions can have a negative effect on air quality and human health. In the commonly used emission algorithms [Guenther et al., 1995], leaf temperature and photosynthetic photon flux density (PPFD) are the driving variables for BVOC emissions. However, in order to better explain the variability over time of BVOC emissions for a given tree species, the most recent emission algorithms, such as MEGAN [Guenther et al., 2006], also consider other driving variables such as phenology, temperature and light history. To validate these new emission algorithms, dynamic branch enclosure BVOC flux measurements have been performed on an adult Fagus sylvatica L. tree in a natural forest environment under ambient PPFD and temperature conditions. Branches at different levels in the canopy were accessible from a 35 m high measurement tower. The cuvette air was analysed on-line with a hs-PTR-MS instrument, which was located in a log cabin at the bottom of the tower. Ion signals related to monoterpenoid compounds (m/z 81 and 137), isoprene (m/z 69), acetone (m/z 59) and methanol (m/z 33) have been measured continuously with the PTR-MS during several phenological periods, from bud-break to senescence. The data show high monoterpenoid emission rates in spring which gradually decrease until leaf fall. Furthermore, monoterpenoid emissions from shaded leaves in the lower layers of the canopy were found to be negligible compared to those from sunlit leaves in the upper layer of the canopy. Effects of light and temperature history on monoterpenoid emissions from Fagus sylvatica L. will be discussed and compared with results obtained in

  13. Variation in Ecophysiological Traits and Drought Tolerance of Beech (Fagus sylvatica L.) Seedlings from Different Populations

    PubMed Central

    Cocozza, Claudia; de Miguel, Marina; Pšidová, Eva; Ditmarová, L'ubica; Marino, Stefano; Maiuro, Lucia; Alvino, Arturo; Czajkowski, Tomasz; Bolte, Andreas; Tognetti, Roberto

    2016-01-01

    Frequency and intensity of heat waves and drought events are expected to increase in Europe due to climate change. European beech (Fagus sylvatica L.) is one of the most important native tree species in Europe. Beech populations originating throughout its native range were selected for common-garden experiments with the aim to determine whether there are functional variations in drought stress responses among different populations. One-year old seedlings from four to seven beech populations were grown and drought-treated in a greenhouse, replicating the experiment at two contrasting sites, in Italy (Mediterranean mountains) and Germany (Central Europe). Experimental findings indicated that: (1) drought (water stress) mainly affected gas exchange describing a critical threshold of drought response between 30 and 26% SWA for photosynthetic rate and Ci/Ca, respectively; (2) the Ci to Ca ratio increased substantially with severe water stress suggesting a stable instantaneous water use efficiency and an efficient regulation capacity of water balance achieved by a tight stomatal control; (3) there was a different response to water stress among the considered beech populations, differently combining traits, although there was not a well-defined variability in drought tolerance. A combined analysis of functional and structural traits for detecting stress signals in beech seedlings is suggested to assess plant performance under limiting moisture conditions and, consequently, to estimate evolutionary potential of beech under a changing environmental scenario. PMID:27446118

  14. Carbon isotope discrimination during branch photosynthesis of Fagus sylvatica: a Bayesian modelling approach.

    PubMed

    Gentsch, Lydia; Hammerle, Albin; Sturm, Patrick; Ogée, Jérôme; Wingate, Lisa; Siegwolf, Rolf; Plüss, Peter; Baur, Thomas; Buchmann, Nina; Knohl, Alexander

    2014-07-01

    Field measurements of photosynthetic carbon isotope discrimination ((13)Δ) of Fagus sylvatica, conducted with branch bags and laser spectrometry, revealed a high variability of (13)Δ, both on diurnal and day-to-day timescales. We tested the prediction capability of three versions of a commonly used model for (13)Δ [called here comprehensive ((13)(Δcomp)), simplified ((13) Δsimple) and revised ((13)(Δrevised)) versions]. A Bayesian approach was used to calibrate major model parameters. Constrained estimates were found for the fractionation during CO(2) fixation in (13)(Δcomp), but not in (13)(Δsimple), and partially for the mesophyll conductance for CO(2)(gi). No constrained estimates were found for fractionations during mitochondrial and photorespiration, and for a diurnally variable apparent fractionation between current assimilates and mitochondrial respiration, specific to (13)(Δrevised). A quantification of parameter estimation uncertainties and interdependencies further helped explore model structure and behaviour. We found that (13)(Δcomp) usually outperformed (13)(Δsimple) because of the explicit consideration of gi and the photorespiratory fractionation in (13)(Δcomp) that enabled a better description of the large observed diurnal variation (≈9‰) of (13)Δ. Flux-weighted daily means of (13)Δ were also better predicted with (13)(Δcomp) than with (13)(Δsimple).

  15. Plant-mediated nitrous oxide emissions from beech (Fagus sylvatica) leaves.

    PubMed

    Pihlatie, Mari; Ambus, Per; Rinne, Janne; Pilegaard, Kim; Vesala, Timo

    2005-10-01

    Nitrous oxide (N2O) emission estimates from forest ecosystems are based currently on emission measurements using soil enclosures. Such enclosures exclude emissions via tall plants and trees and may therefore underestimate the whole-ecosystem N2O emissions. Here, we measured plant-mediated N2O emissions from the leaves of potted beech (Fagus sylvatica) seedlings after fertilizing the soil with 15N-labelled ammonium nitrate (15NH4(15)NO3), and after exposing the roots to elevated concentrations of N2O. Ammonium nitrate fertilization induced N2O + 15N2O emissions from beech leaves. Likewise, the foliage emitted N2O after beech roots were exposed to elevated concentrations of N2O. The average N2O emissions from the fertilization and the root exposure experiments were 0.4 and 2.0 microg N m(-2) leaf area h(-1), respectively. Higher than ambient atmospheric concentrations of N2O in the leaves of the forest trees indicate a potential for canopy N2O emissions in the forest. Our experiments demonstrate the existence of a previously overlooked pathway of N2O to the atmosphere in forest ecosystems, and bring about a need to investigate the magnitude of this phenomenon at larger scales.

  16. Variation in throughfall deposition across a deciduous beech (Fagus sylvatica L.) forest edge in Flanders.

    PubMed

    Devlaeminck, Rebecca; De Schrijver, An; Hermy, Martin

    2005-01-20

    Throughfall deposition and canopy exchange of acidifying and eutrophying compounds and major base cations were studied by means of throughfall analysis in a deciduous beech (Fagus sylvatica L.) forest edge in Belgium over a period of 1 year. Throughfall fluxes of Cl(-), NH(4)(+) and Na(+) were significantly elevated at the forest edge compared to the forest interior. As no edge effect on throughfall water volume could be detected, the observed edge enhancement effects were mainly due to dry deposition and canopy exchange patterns. Indeed, there was an elevated dry deposition of Cl(-), Na(+), K(+), Ca(2+) and Mg(2+) up to 50 m from the field/forest border. Within the forest, throughfall and dry deposition of SO(4)(2-) were highly variable and no significant differences were observed between the forest edge and the forest interior. Leaching of K(+) and Ca(2+) was reduced in the forest edge up to a distance of 30 m from the border. The measured nitrogen and acidic depositions far exceeded the current Flemish critical loads with respect to the protection of biodiversity in forests, especially at the forest edge. This points to an urgent need for controlling emissions as well as the need to consider the elevated deposition load in forest edges when calculating the critical loads in forests.

  17. Living on the Edge: Contrasted Wood-Formation Dynamics in Fagus sylvatica and Pinus sylvestris under Mediterranean Conditions

    PubMed Central

    Martinez del Castillo, Edurne; Longares, Luis A.; Gričar, Jožica; Prislan, Peter; Gil-Pelegrín, Eustaquio; Čufar, Katarina; de Luis, Martin

    2016-01-01

    Wood formation in European beech (Fagus sylvatica L.) and Scots pine (Pinus sylvestris L.) was intra-annually monitored to examine plastic responses of the xylem phenology according to altitude in one of the southernmost areas of their distribution range, i.e., in the Moncayo Natural Park, Spain. The monitoring was done from 2011 to 2013 at 1180 and 1580 m a.s.l., corresponding to the lower and upper limits of European beech forest in this region. Microcores containing phloem, cambium and xylem were collected biweekly from twenty-four trees from the beginning of March to the end of November to assess the different phases of wood formation. The samples were prepared for light microscopy to observe the following phenological phases: onset and end of cell production, onset and end of secondary wall formation in xylem cells and onset of cell maturation. The temporal dynamics of wood formation widely differed among years, altitudes and tree species. For Fagus sylvatica, the onset of cambial activity varied between the first week of May and the third week of June. Cambial activity then slowed down and stopped in summer, resulting in a length of growing season of 48–75 days. In contrast, the growing season for P. sylvestris started earlier and cambium remained active in autumn, leading to a period of activity varying from 139-170 days. The intra-annual wood-formation pattern is site and species-specific. Comparison with other studies shows a clear latitudinal trend in the duration of wood formation, positive for Fagus sylvatica and negative for P. sylvestris. PMID:27047534

  18. Water and lipid relations in beech (Fagus sylvatica L.) seeds and its effect on storage behaviour.

    PubMed

    Pukacka, S; Hoffmann, S K; Goslar, J; Pukacki, P M; Wójkiewicz, E

    2003-04-07

    Beech (Fagus sylvatica L.) seeds indicate intermediate storage behaviour. Properties of water in seed tissues were studied to understand their requirements during storage conditions. Water sorption isotherms showed that at the same relative humidity (RH) the water content is significantly higher in embryo axes than cotyledons. This tendency maintains also after recalculating the water content for zero amount of lipids in tissues. Differential thermal analysis (DTA) indicated water crystallization exotherms in the embryo axes at moisture content (MC) higher than 29% and 16% in the cotyledons. In order to examine the occurrence of glassy state in the cytoplasm of beech embryos as a function of water content, isolated embryo axes were examined using electron spin resonance (ESR) of nitroxide TEMPO probe located inside axes cells. TEMPO molecules undergo fast reorientations with correlation time varied from 2 x 10(-9) s at 180 K to 2 x 10(-11) s at 315 K. Although the TEMPO molecules label mainly the lipid bilayers of cell membranes, they are sensitive to the dynamics and phase transformation of the cytoplasmic cell interior. The label motion is clearly affected by a transition between liquid and glassy state of the cytoplasm. The glass transition temperature (T(g)) raises from 253 to 293 K when water content decreases from 18% to 8%. Far from T(g) the motion is described by Arrhenius equation with very small activation energy E(a) in the liquid state and is relatively small in the glassy state where E(a)=1.5 kJ/mol for 28% H(2)O and E(a)=4.7 kJ/mol for 8% H(2)O or less. The optimal storage conditions of beech seeds are proposed in the range from 255 K for 15% H(2)O to 280 K for 9% H(2)O.

  19. BVOC emissions from English oak (Quercus robur) and European beech (Fagus sylvatica) along a latitudinal gradient

    NASA Astrophysics Data System (ADS)

    van Meeningen, Ylva; Schurgers, Guy; Rinnan, Riikka; Holst, Thomas

    2016-11-01

    English oak (Quercus robur) and European beech (Fagus sylvatica) are amongst the most common tree species growing in Europe, influencing the annual biogenic volatile organic compound (BVOC) budget in this region. Studies have shown great variability in the emissions from these tree species, originating from both genetic variability and differences in climatic conditions between study sites. In this study, we examine the emission patterns for English oak and European beech in genetically identical individuals and the potential variation within and between sites. Leaf scale BVOC emissions, net assimilation rates and stomatal conductance were measured at the International Phenological Garden sites of Ljubljana (Slovenia), Grafrath (Germany) and Taastrup (Denmark). Sampling was conducted during three campaigns between May and July 2014. Our results show that English oak mainly emitted isoprene whilst European beech released monoterpenes. The relative contribution of the most emitted compounds from the two species remained stable across latitudes. The contribution of isoprene for English oak from Grafrath and Taastrup ranged between 92 and 97 % of the total BVOC emissions, whilst sabinene and limonene for European beech ranged from 30.5 to 40.5 and 9 to 15 % respectively for all three sites. The relative contribution of isoprene for English oak at Ljubljana was lower (78 %) in comparison to the other sites, most likely caused by frost damage in early spring. The variability in total leaf-level emission rates from the same site was small, whereas there were greater differences between sites. These differences were probably caused by short-term weather events and plant stress. A difference in age did not seem to affect the emission patterns for the selected trees. This study highlights the significance of within-genotypic variation of BVOC emission capacities for English oak and European beech, the influence of climatic variables such as temperature and light on emission

  20. Unraveling the growth determinism of Fagus sylvatica: a hybrid data-model approach

    NASA Astrophysics Data System (ADS)

    Guillemot, Joannès; Martin-StPaul, Nicolas; Delpierre, Nicolas; François, Christophe; Soudani, Kamel; Restoux, Gwendal; Dufrêne, Eric

    2013-04-01

    The physiological processes underlying the limitation of forest growth are still under debate. Growth has long been considered as a carbone (C) limited process (Sala et al., 2012). As a matter of facts, a recent global meta-analysis has shown good agreements between assimilated C and forest productivity (Litton et al., 2007). Consequently, a majority of the process-based productivity models considers growth as a fraction of the net primary production (NPP) (Lacointe et al., 2000; Sitch et al., 2003. However, investigations at the stand scale report conflicting results (Rocha et al., 2006, Mund et al., 2010) and are not systematically consistent with a strict C limitation of growth, thus challenging the C-centric paradigm. The mechanisms that potentially degrade the link between NPP and growth include: i) the direct effect of environmental factors on growth (Zweifel et al., 2006, Körner et al., 2003), ii) the temporal variability of the growth allocation coefficient, due either to ontogeny (Genet et al., 2009), or to the initial physiological state of the tree i.e. to the reaction to past conditions. Indeed, many dendrochronological and ecological studies have shown a correlation between growth and climatic factors of the previous years (e.g. Lebourgeois et al., 2005; Richardson et al., 2012). In this work, we used a hybrid data model approach in order to assess the determinant of Fagus sylvatica stem growth along a spatial gradient across France. Despite they could brought essential insight on tree functioning, intra-specific studies across contrasted sites are still lacking in the current debate. Standardized annual growth data series at the stand scale were calculated using circumference inventories and dendrochronological series on 17 plots of the RENECOFOR network. We used the process-based model CASTANEA, thoroughly validated in long term flux simulation across Europe (e.g. Delpierre et al. 2009), to simulate the annual NPP of the corresponding periods. We

  1. Changes in BVOC emission pattern from Fagus sylvatica L. measured by thermal desorber GC-MS

    NASA Astrophysics Data System (ADS)

    Joó, É.; van Langenhove, H.; Schietse, L.; Pokorska, O.; Šimpraga, M.; Steppe, K.; Demarcke, M.; Amelynck, C.; Schoon, N.; Müller, J.-F.; Samson, R.; Dewulf, J.

    2009-04-01

    Considerable attention has been focused on biogenic volatile organic compound (BVOC) emissions from forest ecosystems because of their contribution to tropospheric oxidation processes and secondary aerosol formation [1, 2]. It became apparent that biogenic emissions show much more variation than previously assumed. In this poster we focus on the change in BVOC emission patterns from a four year old Fagus sylvatica L. during a growth chamber experiment (PAR, temperature controlled) lasting from March to November 2008. A dynamic branch enclosure system was used in our experiments. Ozone and VOC were removed from air entering the cuvette, as ozone level was found to be a critical parameter for degradation of the compounds [3]. Samples were collected on Tenax TA-Carbotrap solid phase adsorbent tubes and analyzed by TD-GC-MS. Measurements started before budburst of the tree and finished at the end of autumn. Over the entire period 33 samples have been analyzed, while 16 compounds were detected, including 10 monoterpenes (MT), 2 oxygenated-MTs, 2 sesquiterpenes (SQT), isoprene and methyl salicylate. Sabinene showed the highest emission, in an agreement with previous studies [4, 5]. Quantifiable emission appeared 21 days after budburst, and reached the highest level at the beginning of summer. MT emissions showed a clear trend in following each other. As an illustration the trend of sabinene and limonene emission is presented. In the middle of autumn phytophaga infection was observed on the tree induced by Two-spotted mite (Tetranychus urticae). New compounds appeared as a result of infection (linalool, methyl salicylate, (E,E)-α-farnesene, unknown oxygenated-MT, unknown SQT) and became dominant over sabinene, explained by the low MT emissions at this time of the year. These observations point at the importance of further investigation of BVOC emissions (especially SQTs and oxygenated-MTs) and the need for a proper quantification system of these compounds. We would like

  2. Use of sap flow measurements to validate stomatal functions for mature beech (Fagus sylvatica) in view of ozone uptake calculations.

    PubMed

    Braun, Sabine; Schindler, Christian; Leuzinger, Sebastian

    2010-09-01

    For a quantitative estimate of the ozone effect on vegetation reliable models for ozone uptake through the stomata are needed. Because of the analogy of ozone uptake and transpiration it is possible to utilize measurements of water loss such as sap flow for quantification of ozone uptake. This technique was applied in three beech (Fagus sylvatica) stands in Switzerland. A canopy conductance was calculated from sap flow velocity and normalized to values between 0 and 1. It represents mainly stomatal conductance as the boundary layer resistance in forests is usually small. Based on this relative conductance, stomatal functions to describe the dependence on light, temperature, vapour pressure deficit and soil moisture were derived using multivariate nonlinear regression. These functions were validated by comparison with conductance values directly estimated from sap flow. The results corroborate the current flux parameterization for beech used in the DO3SE model.

  3. Monoterpene emissions from Beech ( Fagus sylvatica) in a French forest and impact on secondary pollutants formation at regional scale

    NASA Astrophysics Data System (ADS)

    Moukhtar, S.; Bessagnet, B.; Rouil, L.; Simon, V.

    Biogenic emissions from forest, crops, and grasslands are now considered major compounds in photochemical processes. Air quality analyses require more and more accurate input data, particularly emissions. Unfortunately, depending on the type of vegetation, these emissions are not always reliably defined. For example, Fagus sylvatica, which is a very abundant deciduous tree in France and in Europe, is a weak monoterpene emitter in the European inventory developed by Simpson et al. [1999. Journal of Geophysical Research 104, 8113-8152], but is a strong monoterpene emitter in Luchetta [1999. Caractérisation et quantification dans la basse atmosphère de composés organiques volatils biogéniques et anthropiques contribuant à la pollution de l'air. Ph.D. thesis, INPT Toulouse]. Beech ( F. sylvatica) emission potential has never been measured in France. This study investigates the isoprene and monoterpenes emission measurements from F. sylvatica in France during a research program INTERREG III in Fossé Rhénan, during May and June 2003. A dynamic cuvette method was used. Sabinene is the main monoterpene emitted, composing more than 90% of biogenic emissions. The remaining is composed of α-pinene, β-pinene and limonene. No isoprene emissions were detected. The monoterpene emissions from F. sylvatica are affected by temperature and photosynthetic active radiation (PAR). In order to describe monoterpene emissions, the "isoprene algorithm" developed by Guenther et al. [1991. Journal of Geophysical Research 26A, 10799-10808; 1993. Journal of Geophysical Research 98D, 12609-12617] has been used. With this algorithm, simulation results and observations agree fairly well. The standard emission rate ( T=303K and PAR=1000 μmol m -2 s -1) for total monoterpenes is 43.5 μg g dw-1 h -1. This classifies F. sylvatica as a strong monoterpene emitter. The European inventory [Simpson, et al., 1999. Journal of Geophysical Research 104, 8113-8152], which is the standard inventory of

  4. Effect of flooding on C metabolism of flood-tolerant (Quercus robur) and non-tolerant (Fagus sylvatica) tree species.

    PubMed

    Ferner, Eleni; Rennenberg, Heinz; Kreuzwieser, Jürgen

    2012-02-01

    Flooding is assumed to cause an energy crisis in plants because-due to a lack of O(2)-mitochondrial respiration is replaced by alcoholic fermentation which yields considerably less energy equivalents. In the present study, the effect of flooding on the carbon metabolism of flooding-tolerant pedunculate oak (Quercus robur L.) and flooding-sensitive European beech (Fagus sylvatica L.) seedlings was characterized. Whereas soluble carbohydrate concentrations dropped in roots of F. sylvatica, they were constant in Q. robur during flooding. At the same time, root alcohol dehydrogenase activities were decreased in beech but not in oak, suggesting substrate limitation of alcoholic fermentation in beech roots. Surprisingly, leaf and phloem sap sugar concentrations increased in both species but to a much higher degree in beech. This finding suggests that the phloem unloading process in flooding-sensitive beech was strongly impaired. It is assumed that root-derived ethanol is transported to the leaves via the transpiration stream. This mechanism is considered an adaptation to flooding because it helps avoid the accumulation of toxic ethanol in the roots and supports the whole plant's carbon metabolism by channelling ethanol into the oxidative metabolism of the leaves. A labelling experiment demonstrated that in the leaves of flooded trees, ethanol metabolism does not differ between flooded beech and oak, indicating that processes in the roots are crucial for the trees' flooding tolerance.

  5. Desiccation and Mortality Dynamics in Seedlings of Different European Beech (Fagus sylvatica L.) Populations under Extreme Drought Conditions

    PubMed Central

    Bolte, Andreas; Czajkowski, Tomasz; Cocozza, Claudia; Tognetti, Roberto; de Miguel, Marina; Pšidová, Eva; Ditmarová, Ĺubica; Dinca, Lucian; Delzon, Sylvain; Cochard, Hervè; Ræbild, Anders; de Luis, Martin; Cvjetkovic, Branislav; Heiri, Caroline; Müller, Jürgen

    2016-01-01

    European beech (Fagus sylvatica L., hereafter beech), one of the major native tree species in Europe, is known to be drought sensitive. Thus, the identification of critical thresholds of drought impact intensity and duration are of high interest for assessing the adaptive potential of European beech to climate change in its native range. In a common garden experiment with one-year-old seedlings originating from central and marginal origins in six European countries (Denmark, Germany, France, Romania, Bosnia-Herzegovina, and Spain), we applied extreme drought stress and observed desiccation and mortality processes among the different populations and related them to plant water status (predawn water potential, ΨPD) and soil hydraulic traits. For the lethal drought assessment, we used a critical threshold of soil water availability that is reached when 50% mortality in seedling populations occurs (LD50SWA). We found significant population differences in LD50SWA (10.5–17.8%), and mortality dynamics that suggest a genetic difference in drought resistance between populations. The LD50SWA values correlate significantly with the mean growing season precipitation at population origins, but not with the geographic margins of beech range. Thus, beech range marginality may be more due to climatic conditions than to geographic range. The outcome of this study suggests the genetic variation has a major influence on the varying adaptive potential of the investigated populations. PMID:27379105

  6. Decomposition of beech (Fagus sylvatica) and pine (Pinus nigra) litter along an Alpine elevation gradient: Decay and nutrient release

    PubMed Central

    Berger, Torsten W.; Duboc, Olivier; Djukic, Ika; Tatzber, Michael; Gerzabek, Martin H.; Zehetner, Franz

    2015-01-01

    Litter decomposition is an important process for cycling of nutrients in terrestrial ecosystems. The objective of this study was to evaluate direct and indirect effects of climate on litter decomposition along an altitudinal gradient in a temperate Alpine region. Foliar litter of European beech (Fagus sylvatica) and Black pine (Pinus nigra) was incubated in litterbags during two years in the Hochschwab massif of the Northern Limestone Alps of Austria. Eight incubation sites were selected following an altitudinal/climatic transect from 1900 to 900 m asl. The average remaining mass after two years of decomposition amounted to 54% (beech) and 50% (pine). Net release of N, P, Na, Al, Fe and Mn was higher in pine than in beech litter due to high immobilization (retention) rates of beech litter. However, pine litter retained more Ca than beech litter. Altitude retarded decay (mass loss and associated C release) in beech litter during the first year only but had a longer lasting effect on decaying pine litter. Altitude comprises a suite of highly auto-correlated characteristics (climate, vegetation, litter, soil chemistry, soil microbiology, snow cover) that influence litter decomposition. Hence, decay and nutrient release of incubated litter is difficult to predict by altitude, except during the early stage of decomposition, which seemed to be controlled by climate. Reciprocal litter transplant along the elevation gradient yielded even relatively higher decay of pine litter on beech forest sites after a two-year adaptation period of the microbial community. PMID:26240437

  7. Genome-environment association study suggests local adaptation to climate at the regional scale in Fagus sylvatica.

    PubMed

    Pluess, Andrea R; Frank, Aline; Heiri, Caroline; Lalagüe, Hadrien; Vendramin, Giovanni G; Oddou-Muratorio, Sylvie

    2016-04-01

    The evolutionary potential of long-lived species, such as forest trees, is fundamental for their local persistence under climate change (CC). Genome-environment association (GEA) analyses reveal if species in heterogeneous environments at the regional scale are under differential selection resulting in populations with potential preadaptation to CC within this area. In 79 natural Fagus sylvatica populations, neutral genetic patterns were characterized using 12 simple sequence repeat (SSR) markers, and genomic variation (144 single nucleotide polymorphisms (SNPs) out of 52 candidate genes) was related to 87 environmental predictors in the latent factor mixed model, logistic regressions and isolation by distance/environmental (IBD/IBE) tests. SSR diversity revealed relatedness at up to 150 m intertree distance but an absence of large-scale spatial genetic structure and IBE. In the GEA analyses, 16 SNPs in 10 genes responded to one or several environmental predictors and IBE, corrected for IBD, was confirmed. The GEA often reflected the proposed gene functions, including indications for adaptation to water availability and temperature. Genomic divergence and the lack of large-scale neutral genetic patterns suggest that gene flow allows the spread of advantageous alleles in adaptive genes. Thereby, adaptation processes are likely to take place in species occurring in heterogeneous environments, which might reduce their regional extinction risk under CC.

  8. Diversity and Composition of the Leaf Mycobiome of Beech (Fagus sylvatica) Are Affected by Local Habitat Conditions and Leaf Biochemistry

    PubMed Central

    Unterseher, Martin; Siddique, Abu Bakar; Brachmann, Andreas; Peršoh, Derek

    2016-01-01

    Comparative investigations of plant-associated fungal communities (mycobiomes) in distinct habitats and under distinct climate regimes have been rarely conducted in the past. Nowadays, high-throughput sequencing allows routine examination of mycobiome responses to environmental changes and results at an unprecedented level of detail. In the present study, we analysed Illumina-generated fungal ITS1 sequences from European beech (Fagus sylvatica) originating from natural habitats at two different altitudes in the German Alps and from a managed tree nursery in northern Germany. In general, leaf-inhabiting mycobiome diversity and composition correlated significantly with the origin of the trees. Under natural condition the mycobiome was more diverse at lower than at higher elevation, whereas fungal diversity was lowest in the artificial habitat of the tree nursery. We further identified significant correlation of leaf chlorophylls and flavonoids with both habitat parameters and mycobiome biodiversity. The present results clearly point towards a pronounced importance of local stand conditions for the structure of beech leaf mycobiomes and for a close interrelation of phyllosphere fungi and leaf physiology. PMID:27078859

  9. Raman spectroscopic investigation of 13CO 2 labeling and leaf dark respiration of Fagus sylvatica L. (European beech).

    PubMed

    Keiner, Robert; Gruselle, Marie-Cécile; Michalzik, Beate; Popp, Jürgen; Frosch, Torsten

    2015-03-01

    An important issue, in times of climate change and more extreme weather events, is the investigation of forest ecosystem reactions to these events. Longer drought periods stress the vitality of trees and promote mass insect outbreaks, which strongly affect ecosystem processes and services. Cavity-enhanced Raman gas spectrometry was applied for online multi-gas analysis of the gas exchange rates of O2 and CO2 and the labeling of Fagus sylvatica L. (European beech) seedlings with (13)CO2. The rapid monitoring of all these gases simultaneously allowed for the separation of photosynthetic uptake of CO2 by the beech seedlings and a constant (12)CO2 efflux via respiration and thus for a correction of the measured (12)CO2 concentrations in course of the labeling experiment. The effects of aphid infestation with the woolly beech aphid (Phyllaphis fagi L.) as well as the effect of a drought period on the respirational gas exchange were investigated. A slightly decreased respirational activity of drought-stressed seedlings in comparison to normally watered seedlings was found already for a low drought intensity. Cavity-enhanced Raman gas monitoring of O2, (12)CO2, and (13)CO2 was proven to be a powerful new tool for studying the effect of drought stress and aphid infestation on the respirational activity of European beech seedlings as an example of important forest species in Central Europe.

  10. Decomposition of beech (Fagus sylvatica) and pine (Pinus nigra) litter along an Alpine elevation gradient: Decay and nutrient release.

    PubMed

    Berger, Torsten W; Duboc, Olivier; Djukic, Ika; Tatzber, Michael; Gerzabek, Martin H; Zehetner, Franz

    2015-08-01

    Litter decomposition is an important process for cycling of nutrients in terrestrial ecosystems. The objective of this study was to evaluate direct and indirect effects of climate on litter decomposition along an altitudinal gradient in a temperate Alpine region. Foliar litter of European beech (Fagus sylvatica) and Black pine (Pinus nigra) was incubated in litterbags during two years in the Hochschwab massif of the Northern Limestone Alps of Austria. Eight incubation sites were selected following an altitudinal/climatic transect from 1900 to 900 m asl. The average remaining mass after two years of decomposition amounted to 54% (beech) and 50% (pine). Net release of N, P, Na, Al, Fe and Mn was higher in pine than in beech litter due to high immobilization (retention) rates of beech litter. However, pine litter retained more Ca than beech litter. Altitude retarded decay (mass loss and associated C release) in beech litter during the first year only but had a longer lasting effect on decaying pine litter. Altitude comprises a suite of highly auto-correlated characteristics (climate, vegetation, litter, soil chemistry, soil microbiology, snow cover) that influence litter decomposition. Hence, decay and nutrient release of incubated litter is difficult to predict by altitude, except during the early stage of decomposition, which seemed to be controlled by climate. Reciprocal litter transplant along the elevation gradient yielded even relatively higher decay of pine litter on beech forest sites after a two-year adaptation period of the microbial community.

  11. The influence of O3, NO2 and SO2 on growth of Picea abies and Fagus sylvatica in the Carpathian Mountains.

    PubMed

    Muzika, R M; Guyette, R P; Zielonka, T; Liebhold, A M

    2004-07-01

    At 17 long-term pollution monitoring sites throughout the Carpathian Mountains, tree growth patterns and variation in growth rate were examined to determine relationship of tree growth to specific pollutants. Canopy dominant Picea abies and Fagus sylvatica were selected at each site. Basal area increment (BAI) values were calculated from raw ring widths and used as an estimate of tree growth. Across all sites, BAI chronologies were highly variable, therefore local conditions and forest structure accounted for considerable variation. Several significant relationships, however, implicated a role of pollutants on tree growth. Average levels (1997-1999) of NO(2) and SO(2) were inversely related to BAI means (1989-1999). Although average O(3) alone was not related to growth, the maximum O(3) value reported at the sites was negatively correlated with overall growth. A variable representing the combined effect of O(3), NO(2) and SO(2) was negatively correlated with both P. abies and F. sylvatica growth. Pollution data were used to categorize all sites into 'high' or 'low' pollution sites. Difference chronologies based on these categories indicated trends of decline in the 'high' pollution sites relative to 'low' pollution site. In the more heavily polluted sites, the BAI of Fagus sylvatica has declined approximately 50% and Picea abies has declined 20% over the past 45 years.

  12. Interactive effects of juvenile defoliation, light conditions, and interspecific competition on growth and ectomycorrhizal colonization of Fagus sylvatica and Pinus sylvestris seedlings.

    PubMed

    Trocha, Lidia K; Weiser, Ewa; Robakowski, Piotr

    2016-01-01

    Seedlings of forest tree species are exposed to a number of abiotic (organ loss or damage, light shortage) and biotic (interspecific competition) stress factors, which may lead to an inhibition of growth and reproduction and, eventually, to plant death. Growth of the host and its mycorrhizal symbiont is often closely linked, and hence, host damage may negatively affect the symbiont. We designed a pot experiment to study the response of light-demanding Pinus sylvestris and shade-tolerant Fagus sylvatica seedlings to a set of abiotic and biotic stresses and subsequent effects on ectomycorrhizal (ECM) root tip colonization, seedling biomass, and leaf nitrogen content. The light regime had a more pronounced effect on ECM colonization than did juvenile damage. The interspecific competition resulted in higher ECM root tip abundance for Pinus, but this effect was insignificant in Fagus. Low light and interspecific competition resulted in lower seedling biomass compared to high light, and the effect of the latter was partially masked by high light. Leaf nitrogen responded differently in Fagus and Pinus when they grew in interspecific competition. Our results indicated that for both light-demanding (Pinus) and shade-tolerant (Fagus) species, the light environment was a major factor affecting seedling growth and ECM root tip abundance. The light conditions favorable for the growth of seedlings may to some extent compensate for the harmful effects of juvenile organ loss or damage and interspecific competition.

  13. Tree Species Composition and Harvest Intensity Affect Herbivore Density and Leaf Damage on Beech, Fagus sylvatica, in Different Landscape Contexts.

    PubMed

    Mangels, Jule; Blüthgen, Nico; Frank, Kevin; Grassein, Fabrice; Hilpert, Andrea; Mody, Karsten

    2015-01-01

    Most forests are exposed to anthropogenic management activities that affect tree species composition and natural ecosystem processes. Changes in ecosystem processes such as herbivory depend on management intensity, and on regional environmental conditions and species pools. Whereas influences of specific forest management measures have already been addressed for different herbivore taxa on a local scale, studies considering effects of different aspects of forest management across different regions are rare. We assessed the influence of tree species composition and intensity of harvesting activities on arthropod herbivores and herbivore-related damage to beech trees, Fagus sylvatica, in 48 forest plots in three regions of Germany. We found that herbivore abundance and damage to beech trees differed between regions and that - despite the regional differences - density of tree-associated arthropod taxa and herbivore damage were consistently affected by tree species composition and harvest intensity. Specifically, overall herbivore damage to beech trees increased with increasing dominance of beech trees - suggesting the action of associational resistance processes - and decreased with harvest intensity. The density of leaf chewers and mines was positively related to leaf damage, and several arthropod groups responded to beech dominance and harvest intensity. The distribution of damage patterns was consistent with a vertical shift of herbivores to higher crown layers during the season and with higher beech dominance. By linking quantitative data on arthropod herbivore abundance and herbivory with tree species composition and harvesting activity in a wide variety of beech forests, our study helps to better understand the influence of forest management on interactions between a naturally dominant deciduous forest tree and arthropod herbivores.

  14. Comparison of pollen gene flow among four European beech (Fagus sylvatica L.) populations characterized by different management regimes.

    PubMed

    Piotti, A; Leonardi, S; Buiteveld, J; Geburek, T; Gerber, S; Kramer, K; Vettori, C; Vendramin, G G

    2012-03-01

    The study of the dispersal capability of a species can provide essential information for the management and conservation of its genetic variability. Comparison of gene flow rates among populations characterized by different management and evolutionary histories allows one to decipher the role of factors such as isolation and tree density on gene movements. We used two paternity analysis approaches and different strategies to handle the possible presence of genotyping errors to obtain robust estimates of pollen flow in four European beech (Fagus sylvatica L.) populations from Austria and France. In each country one of the two plots is located in an unmanaged forest; the other plots are managed with a shelterwood system and inside a colonization area (in Austria and France, respectively). The two paternity analysis approaches provided almost identical estimates of gene flow. In general, we found high pollen immigration (~75% of pollen from outside), with the exception of the plot from a highly isolated forest remnant (~50%). In the two unmanaged plots, the average within-population pollen dispersal distances (from 80 to 184 m) were higher than previously estimated for beech. From the comparison between the Austrian managed and unmanaged plots, that are only 500 m apart, we found no evidence that either gene flow or reproductive success distributions were significantly altered by forest management. The investigated phenotypic traits (crown area, height, diameter and flowering phenology) were not significantly related with male reproductive success. Shelterwood seems to have an effect on the distribution of within-population pollen dispersal distances. In the managed plot, pollen dispersal distances were shorter, possibly because adult tree density is three-fold (163 versus 57 trees per hectare) with respect to the unmanaged one.

  15. Tree Species Composition and Harvest Intensity Affect Herbivore Density and Leaf Damage on Beech, Fagus sylvatica, in Different Landscape Contexts

    PubMed Central

    Mangels, Jule; Blüthgen, Nico; Frank, Kevin; Grassein, Fabrice; Hilpert, Andrea; Mody, Karsten

    2015-01-01

    Most forests are exposed to anthropogenic management activities that affect tree species composition and natural ecosystem processes. Changes in ecosystem processes such as herbivory depend on management intensity, and on regional environmental conditions and species pools. Whereas influences of specific forest management measures have already been addressed for different herbivore taxa on a local scale, studies considering effects of different aspects of forest management across different regions are rare. We assessed the influence of tree species composition and intensity of harvesting activities on arthropod herbivores and herbivore-related damage to beech trees, Fagus sylvatica, in 48 forest plots in three regions of Germany. We found that herbivore abundance and damage to beech trees differed between regions and that – despite the regional differences - density of tree-associated arthropod taxa and herbivore damage were consistently affected by tree species composition and harvest intensity. Specifically, overall herbivore damage to beech trees increased with increasing dominance of beech trees – suggesting the action of associational resistance processes – and decreased with harvest intensity. The density of leaf chewers and mines was positively related to leaf damage, and several arthropod groups responded to beech dominance and harvest intensity. The distribution of damage patterns was consistent with a vertical shift of herbivores to higher crown layers during the season and with higher beech dominance. By linking quantitative data on arthropod herbivore abundance and herbivory with tree species composition and harvesting activity in a wide variety of beech forests, our study helps to better understand the influence of forest management on interactions between a naturally dominant deciduous forest tree and arthropod herbivores. PMID:25938417

  16. Comparison of pollen gene flow among four European beech (Fagus sylvatica L.) populations characterized by different management regimes

    PubMed Central

    Piotti, A; Leonardi, S; Buiteveld, J; Geburek, T; Gerber, S; Kramer, K; Vettori, C; Vendramin, G G

    2012-01-01

    The study of the dispersal capability of a species can provide essential information for the management and conservation of its genetic variability. Comparison of gene flow rates among populations characterized by different management and evolutionary histories allows one to decipher the role of factors such as isolation and tree density on gene movements. We used two paternity analysis approaches and different strategies to handle the possible presence of genotyping errors to obtain robust estimates of pollen flow in four European beech (Fagus sylvatica L.) populations from Austria and France. In each country one of the two plots is located in an unmanaged forest; the other plots are managed with a shelterwood system and inside a colonization area (in Austria and France, respectively). The two paternity analysis approaches provided almost identical estimates of gene flow. In general, we found high pollen immigration (∼75% of pollen from outside), with the exception of the plot from a highly isolated forest remnant (∼50%). In the two unmanaged plots, the average within-population pollen dispersal distances (from 80 to 184 m) were higher than previously estimated for beech. From the comparison between the Austrian managed and unmanaged plots, that are only 500 m apart, we found no evidence that either gene flow or reproductive success distributions were significantly altered by forest management. The investigated phenotypic traits (crown area, height, diameter and flowering phenology) were not significantly related with male reproductive success. Shelterwood seems to have an effect on the distribution of within-population pollen dispersal distances. In the managed plot, pollen dispersal distances were shorter, possibly because adult tree density is three-fold (163 versus 57 trees per hectare) with respect to the unmanaged one. PMID:21897442

  17. Tree-Ring Stable Isotopes Reveal Twentieth-Century Increases in Water-Use Efficiency of Fagus sylvatica and Nothofagus spp. in Italian and Chilean Mountains

    PubMed Central

    Tognetti, Roberto; Lombardi, Fabio; Lasserre, Bruno; Cherubini, Paolo; Marchetti, Marco

    2014-01-01

    Changes in intrinsic water use efficiency (iWUE) were investigated in Fagus sylvatica and Nothofagus spp. over the last century. We combined dendrochronological methods with dual-isotope analysis to investigate whether atmospheric changes enhanced iWUE of Fagus and Nothofagus and tree growth (basal area increment, BAI) along latitudinal gradients in Italy and Chile. Post-maturation phases of the trees presented different patterns in δ13C, Δ13C, δ18O, Ci (internal CO2 concentration), iWUE, and BAI. A continuous enhancement in isotope-derived iWUE was observed throughout the twentieth century, which was common to all sites and related to changes in Ca (ambient CO2 concentration) and secondarily to increases in temperature. In contrast to other studies, we observed a general increasing trend of BAI, with the exception of F. sylvatica in Aspromonte. Both iWUE and BAI were uncoupled with the estimated drought index, which is in agreement with the absence of enduring decline in tree growth. In general, δ13C and δ18O showed a weak relationship, suggesting the major influence of photosynthetic rate on Ci and δ13C, and the minor contribution of the regulation of stomatal conductance to iWUE. The substantial warming observed during the twentieth century did not result in a clear pattern of increased drought stress along these latitudinal transects, because of the variability in temporal trends of precipitation and in specific responses of populations. PMID:25398040

  18. Stomatal ozone flux and visible leaf injury in native juvenile trees of Fagus sylvatica L.: a field study from the Jizerske hory Mts., the Czech Republic.

    PubMed

    Vlasáková-Matoušková, Leona; Hůnová, Iva

    2015-07-01

    The study was carried out at six sites in the Jizerskehory Mts. in the north of the Czech Republic. At all these sites, ranging in altitude between 460 and 962 m a. s. l., and during the period from June to September in 2008, O3 concentrations and environmental parameters important for accumulated stomatal O3 flux (AFst) into Fagus sylvatica leaves were measured. At five sites, visible injury on Fagus sylvatica L. juvenile tree leaves was observed. A combination of actual O3 levels in the Jizerkehory Mts. and environmental conditions, though relative air humidity and air temperature significantly limited stomatal conductance, has been sufficient enough to cause O3 uptake exceeding the critical level (CL) for forest ecosystems. The AFst values ranged between 13.4 and 22.3 mmol O3 m(-2). The CL for the accumulated stomatal flux of O3 above a flux threshold 1.6 nmol m(-2) s(-1) (AFst1.6) was exceeded at all sites from ca 45 to 270% (160% on average). The CL of 5 ppm h(-1) for AOT40 (accumulated O3 exposure above threshold of 40 ppb) was exceeded at four sites. The relationship between visible injury on O3 indices was found. The conclusions based on AOT40 and AFSt are not the same. AFSt has been determined as better predictor of visible injury than AOT40.

  19. What are the functional mechanisms underlying forest decline? A case study on a European beech (Fagus sylvatica L.) stand.

    NASA Astrophysics Data System (ADS)

    Delaporte, Alice; Bazot, Stéphane; Fresneau, Chantal; Damesin, Claire

    2013-04-01

    The ongoing climate change is altering the precipitation patterns (abundance and frequency) of most parts of the world. The consequences of these changes on forests are already visible through frequent declines. A lot of them can be linked to the occurrence of long and/or repeated drought periods. Although forest decline could severely impact the nutrient and water cycles, their underlying functional causes are not well understood. Two main hypotheses have been proposed to explain the mechanisms of decline at the tree level: • Carbon reserves deficit ("carbon starvation") • Loss of water transport ( "hydraulic failure") Although hydraulic failure has been observed in a wetland species decline (poplar), our understanding of forest decline is still lacking in many species. Our study concerns a widespread species, European beech (Fagus sylvatica L.). A severely declining mature beech plot in the Fontainebleau state forest (France) was followed. This decline can be related to repeated droughts, enhanced by unfavorable soil conditions (sandy soil with very low extractible soil water). For the first time to our knowledge, an integrative in situ functional approach coupling both hydraulic and carbon, but also nitrogen functioning was developed. More precisely, pre-dawn and midday water potentials, "native" embolism, and embolism vulnerability of branches, radial tree growth, carbon and nitrogen reserves concentrations, were measured on healthy and declining trees. Our results showed that under normal climatic conditions (summer 2012), pre-dawn and midday water potentials were the same for healthy and declining trees throughout the season. Their losses of hydraulic conductivity ("native" embolism) were not significantly different, even at the end of the summer. Moreover, the embolism vulnerability curves also showed no significant difference (50% loss of hydraulic conductivity at around - 3MPa). Concerning C and N reserves concentrations, we showed that seasonal

  20. Transport of soluble carbohydrates in temperate deciduous trees: beech (Fagus sylvatica) and ash (Fraxinus excelsior) in comparison

    NASA Astrophysics Data System (ADS)

    Thoms, Ronny; Köhler, Michael; Gessler, Arthur; Gleixner, Gerd

    2015-04-01

    The structure of phloem cells and the physiology of the transport of soluble carbohydrates in plants are well studied. However, the influence of different phloem un- and uploading strategies on the translocation of carbohydrates in different tree species is largely unknown. Therefore, we conducted a pulse labeling on 20 young trees of European beech (Fagus sylvatica) and European ash (Fraxinus excelsior) respectively, using the stable isotope 13C in a temperate deciduous forest in Central Germany. In one growing season each tree species was labeled in a closed transparent plastic chamber with 99% 13CO2 for 5 h. The compound specific δ 13C from carbohydrates in the different compartments leaf, branch, stem and root was measured by high-performance liquid chromatography linked with an isotope ratio mass spectrometer (HPLC-IRMS). We found that both tree species used sucrose as a transport sugar, but carbohydrates of the raffinose group (RFO) served as main transport sugar in ash trees. This indicate that beech used only the apoplastic loading strategy into the phloem cells while ash trees relied on both, apoplastic and symplastic loading, preferring the latter at the end of the growing season. Furthermore, we observed different transport velocities of labeled sugars in the two species. Here, sucrose in beech and carbohydrates of the RFO in ash were transported fastest, whereas sucrose was constantly slowest in ash trees. The label of carbohydrates was found over 60 day in the roots of both tree species, with the highest δ 13C enrichment in carbohydrates of RFO than in the other sugars. Accordingly, the mean residence time (MRT) and half life time (HLT) of 13C in different compartments were longest for carbohydrates of RFO in roots (25.6 days) and sucrose in stems (14.9 days), while the shortest MRT and HLT for sucrose appeared in beech in all compartments. Our results give evidence that RFO are preferentially transported to the root tissue as an agent against frost

  1. Influence of litter chemistry and stoichiometry on glucan depolymerization during decomposition of beech (Fagus sylvatica L.) litter.

    PubMed

    Leitner, Sonja; Wanek, Wolfgang; Wild, Birgit; Haemmerle, Ieda; Kohl, Lukas; Keiblinger, Katharina M; Zechmeister-Boltenstern, Sophie; Richter, Andreas

    2012-07-01

    Glucans like cellulose and starch are a major source of carbon for decomposer food webs, especially during early- and intermediate-stages of decomposition. Litter quality has previously been suggested to notably influence decomposition processes as it determines the decomposability of organic material and the nutrient availability to the decomposer community. To study the impact of chemical and elemental composition of resources on glucan decomposition, a laboratory experiment was carried out using beech (Fagus sylvatica, L.) litter from four different locations in Austria, differing in composition (concentration of starch, cellulose and acid unhydrolyzable residue or AUR fraction) and elemental stoichiometry (C:N:P ratio). Leaf litter was incubated in mesocosms for six months in the laboratory under controlled conditions. To investigate the process of glucan decomposition and its controls, we developed an isotope pool dilution (IPD) assay using (13)C-glucose to label the pool of free glucose in the litter, and subsequently measured the dilution of label over time. This enabled us to calculate gross rates of glucose production through glucan depolymerization, and glucose consumption by the microbial community. In addition, potential activities of extracellular cellulases and ligninases (peroxidases and phenoloxidases) were measured to identify effects of resource chemistry and stoichiometry on microbial enzyme production. Gross rates of glucan depolymerization and glucose consumption were highly correlated, indicating that both processes are co-regulated and intrinsically linked by the microbial demand for C and energy and thereby to resource allocation to enzymes that depolymerize glucans. At early stages of decomposition, glucan depolymerization rates were correlated with starch content, indicating that starch was the primary source for glucose. With progressing litter decomposition, the correlation with starch diminished and glucan depolymerization rates were

  2. Influence of tree internal nitrogen reserves on the response of beech (Fagus sylvatica) trees to elevated atmospheric carbon dioxide concentration.

    PubMed

    Dyckmans, Jens; Flessa, Heiner

    2002-01-01

    We examined the influence of plant internal nitrogen (N) reserves on the response of 3-year-old beech (Fagus sylvatica L.) trees to elevated atmospheric CO2 concentration ([CO2]) in a dual 15N and 13C long-term labeling experiment. Trees were grown on sand and received either no N nutrition (-N treatment) or 4 mM N (+N treatment) for 1 year. The -N and +N pretreated trees were then placed in growth chambers and grown in 350 (ambient) or 700 ppm (elevated) of a 13CO2 atmosphere for 24 weeks. In all treatments, trees were supplied with 4 mM 15N during the experiment. Irrespective of tree N reserves, elevated [CO2] increased cumulative carbon (C) uptake by about 30% at Week 24 compared with that for trees in the ambient treatment. Elevated [CO2] also caused a shift in C allocation to belowground compartments, which was more pronounced in -N trees than in +N trees. In +N trees, belowground allocation of new C at Week 24 was 67% in ambient [CO2] compared with 70% in elevated [CO2]. The corresponding values for -N trees were 70 and 79%. The increase in C allocation in response to elevated [CO2] was most evident as an increase in belowground respiration; however, specific root respiration was unaffected by the CO2 or N treatments. Although elevated [CO2] increased root growth and belowground respiration, it had no effect on N uptake at Week 24. As a result of increased C uptake, N concentrations were decreased in trees in the elevated [CO2] treatment compared with trees in the ambient treatment in both N treatments. Partitioning of new N uptake was unaffected by elevated [CO2] in +N trees. In -N trees, however, N allocation to the stem decreased in response to elevated [CO2] and N allocation to fine roots increased, suggesting a reduction in the formation of N reserves in response to elevated [CO2]. We conclude that the response of beech trees to elevated [CO2] is affected by internal N status and that elevated [CO2] may influence the ability of the trees to form N

  3. Beech wood Fagus sylvatica dilute-acid hydrolysate as a feedstock to support Chlorella sorokiniana biomass, fatty acid and pigment production.

    PubMed

    Miazek, Krystian; Remacle, Claire; Richel, Aurore; Goffin, Dorothee

    2017-04-01

    This work evaluates the possibility of using beech wood (Fagus sylvatica) dilute-acid (H2SO4) hydrolysate as a feedstock for Chlorella sorokiniana growth, fatty acid and pigment production. Neutralized wood acid hydrolysate, containing organic and mineral compounds, was tested on Chlorella growth at different concentrations and compared to growth under phototrophic conditions. Chlorella growth was improved at lower loadings and inhibited at higher loadings. Based on these results, a 12% neutralized wood acid hydrolysate (Hyd12%) loading was selected to investigate its impact on Chlorella growth, fatty acid and pigment production. Hyd12% improved microalgal biomass, fatty acid and pigment productivities both in light and in dark, when compared to photoautotrophic control. Light intensity had substantial influence on fatty acid and pigment composition in Chlorella culture during Hyd12%-based growth. Moreover, heterotrophic Chlorella cultivation with Hyd12% also showed that wood hydrolysate can constitute an attractive feedstock for microalgae cultivation in case of lack of light.

  4. A unigene set for European beech (Fagus sylvatica L.) and its use to decipher the molecular mechanisms involved in dormancy regulation.

    PubMed

    Lesur, Isabelle; Bechade, Alison; Lalanne, Céline; Klopp, Christophe; Noirot, Céline; Leplé, Jean-Charles; Kremer, Antoine; Plomion, Christophe; Le Provost, Grégoire

    2015-09-01

    Systematic sequencing is the method of choice for generating genomic resources for molecular marker development and candidate gene identification in nonmodel species. We generated 47,357 Sanger ESTs and 2.2M Roche-454 reads from five cDNA libraries for European beech (Fagus sylvatica L.). This tree species of high ecological and economic value in Europe is among the most representative trees of deciduous broadleaf forests. The sequences generated were assembled into 21,057 contigs with MIRA software. Functional annotations were obtained for 85% of these contigs, from the proteomes of four plant species, Swissprot accessions and the Gene Ontology database. We were able to identify 28,079 in silico SNPs for future marker development. Moreover, RNAseq and qPCR approaches identified genes and gene networks regulated differentially between two critical phenological stages preceding vegetative bud burst (the quiescent and swelling buds stages). According to climatic model-based projection, some European beech populations may be endangered, particularly at the southern and eastern edges of the European distribution range, which are strongly affected by current climate change. This first genomic resource for the genus Fagus should facilitate the identification of key genes for beech adaptation and management strategies for preserving beech adaptability.

  5. Co-occurrence patterns of trees along macro-climatic gradients and their potential influence on the present and future distribution of Fagus sylvatica L.

    USGS Publications Warehouse

    Meier, E.S.; Edwards, T.C.; Kienast, Felix; Dobbertin, M.; Zimmermann, N.E.

    2011-01-01

    Aim During recent and future climate change, shifts in large-scale species ranges are expected due to the hypothesized major role of climatic factors in regulating species distributions. The stress-gradient hypothesis suggests that biotic interactions may act as major constraints on species distributions under more favourable growing conditions, while climatic constraints may dominate under unfavourable conditions. We tested this hypothesis for one focal tree species having three major competitors using broad-scale environmental data. We evaluated the variation of species co-occurrence patterns in climate space and estimated the influence of these patterns on the distribution of the focal species for current and projected future climates.Location Europe.Methods We used ICP Forest Level 1 data as well as climatic, topographic and edaphic variables. First, correlations between the relative abundance of European beech (Fagus sylvatica) and three major competitor species (Picea abies, Pinus sylvestris and Quercus robur) were analysed in environmental space, and then projected to geographic space. Second, a sensitivity analysis was performed using generalized additive models (GAM) to evaluate where and how much the predicted F. sylvatica distribution varied under current and future climates if potential competitor species were included or excluded. We evaluated if these areas coincide with current species co-occurrence patterns.Results Correlation analyses supported the stress-gradient hypothesis: towards favourable growing conditions of F. sylvatica, its abundance was strongly linked to the abundance of its competitors, while this link weakened towards unfavourable growing conditions, with stronger correlations in the south and at low elevations than in the north and at high elevations. The sensitivity analysis showed a potential spatial segregation of species with changing climate and a pronounced shift of zones where co-occurrence patterns may play a major role

  6. Molecular organization of the 25S-18S rDNA IGS of Fagus sylvatica and Quercus suber: a comparative analysis.

    PubMed

    Inácio, Vera; Rocheta, Margarida; Morais-Cecílio, Leonor

    2014-01-01

    The 35S ribosomal DNA (rDNA) units, repeated in tandem at one or more chromosomal loci, are separated by an intergenic spacer (IGS) containing functional elements involved in the regulation of transcription of downstream rRNA genes. In the present work, we have compared the IGS molecular organizations in two divergent species of Fagaceae, Fagus sylvatica and Quercus suber, aiming to comprehend the evolution of the IGS sequences within the family. Self- and cross-hybridization FISH was done on representative species of the Fagaceae. The IGS length variability and the methylation level of 18 and 25S rRNA genes were assessed in representatives of three genera of this family: Fagus, Quercus and Castanea. The intergenic spacers in Beech and Cork Oak showed similar overall organizations comprising putative functional elements needed for rRNA gene activity and containing a non-transcribed spacer (NTS), a promoter region, and a 5'-external transcribed spacer. In the NTS: the sub-repeats structure in Beech is more organized than in Cork Oak, sharing some short motifs which results in the lowest sequence similarity of the entire IGS; the AT-rich region differed in both spacers by a GC-rich block inserted in Cork Oak. The 5'-ETS is the region with the higher similarity, having nonetheless different lengths. FISH with the NTS-5'-ETS revealed fainter signals in cross-hybridization in agreement with the divergence between genera. The diversity of IGS lengths revealed variants from ∼ 2 kb in Fagus, and Quercus up to 5.3 kb in Castanea, and a lack of correlation between the number of variants and the number of rDNA loci in several species. Methylation of 25S Bam HI site was confirmed in all species and detected for the first time in the 18S of Q. suber and Q. faginea. These results provide important clues for the evolutionary trends of the rDNA 25S-18S IGS in the Fagaceae family.

  7. Canopy-level stomatal narrowing in adult Fagus sylvatica under O3 stress - means of preventing enhanced O3 uptake under high O3 exposure?

    PubMed

    Matyssek, R; Baumgarten, M; Hummel, U; Häberle, K-H; Kitao, M; Wieser, G

    2015-01-01

    Spatio-temporally consistent O(3) doses are demonstrated in adult Fagus sylvatica from the Kranzberg Forest free-air fumigation experiment, covering cross-canopy and whole-seasonal scopes through sap flow measurement. Given O(3)-driven closure of stomata, we hypothesized enhanced whole-tree level O(3) influx to be prevented under enhanced O(3) exposure. Although foliage transpiration rate was lowered under twice-ambient O(3) around noon by 30% along with canopy conductance, the hypothesis was falsified, as O(3) influx was raised by 25%. Nevertheless, the twice-ambient/ambient ratio of O(3) uptake was smaller by about 20% than that of O(3) exposure, suggesting stomatal limitation of uptake. The O(3) response was traceable from leaves across branches to the canopy, where peak transpiration rates resembled those of shade rather than sun branches. Rainy/overcast-day and nightly O(3) uptake is quantified and discussed. Whole-seasonal canopy-level validation of modelled with sap flow-derived O(3) flux becomes available in assessing O(3) risk for forest trees.

  8. Detecting short spatial scale local adaptation and epistatic selection in climate-related candidate genes in European beech (Fagus sylvatica) populations.

    PubMed

    Csilléry, Katalin; Lalagüe, Hadrien; Vendramin, Giovanni G; González-Martínez, Santiago C; Fady, Bruno; Oddou-Muratorio, Sylvie

    2014-10-01

    Detecting signatures of selection in tree populations threatened by climate change is currently a major research priority. Here, we investigated the signature of local adaptation over a short spatial scale using 96 European beech (Fagus sylvatica L.) individuals originating from two pairs of populations on the northern and southern slopes of Mont Ventoux (south-eastern France). We performed both single and multilocus analysis of selection based on 53 climate-related candidate genes containing 546 SNPs. FST outlier methods at the SNP level revealed a weak signal of selection, with three marginally significant outliers in the northern populations. At the gene level, considering haplotypes as alleles, two additional marginally significant outliers were detected, one on each slope. To account for the uncertainty of haplotype inference, we averaged the Bayes factors over many possible phase reconstructions. Epistatic selection offers a realistic multilocus model of selection in natural populations. Here, we used a test suggested by Ohta based on the decomposition of the variance of linkage disequilibrium. Overall populations, 0.23% of the SNP pairs (haplotypes) showed evidence of epistatic selection, with nearly 80% of them being within genes. One of the between gene epistatic selection signals arose between an FST outlier and a nonsynonymous mutation in a drought response gene. Additionally, we identified haplotypes containing selectively advantageous allele combinations which were unique to high or low elevations and northern or southern populations. Several haplotypes contained nonsynonymous mutations situated in genes with known functional importance for adaptation to climatic factors.

  9. Enhanced ozone strongly reduces carbon sink strength of adult beech (Fagus sylvatica)--resume from the free-air fumigation study at Kranzberg Forest.

    PubMed

    Matyssek, R; Wieser, G; Ceulemans, R; Rennenberg, H; Pretzsch, H; Haberer, K; Löw, M; Nunn, A J; Werner, H; Wipfler, P; Osswald, W; Nikolova, P; Hanke, D E; Kraigher, H; Tausz, M; Bahnweg, G; Kitao, M; Dieler, J; Sandermann, H; Herbinger, K; Grebenc, T; Blumenröther, M; Deckmyn, G; Grams, T E E; Heerdt, C; Leuchner, M; Fabian, P; Häberle, K-H

    2010-08-01

    Ground-level ozone (O(3)) has gained awareness as an agent of climate change. In this respect, key results are comprehended from a unique 8-year free-air O(3)-fumigation experiment, conducted on adult beech (Fagus sylvatica) at Kranzberg Forest (Germany). A novel canopy O(3) exposure methodology was employed that allowed whole-tree assessment in situ under twice-ambient O(3) levels. Elevated O(3) significantly weakened the C sink strength of the tree-soil system as evidenced by lowered photosynthesis and 44% reduction in whole-stem growth, but increased soil respiration. Associated effects in leaves and roots at the gene, cell and organ level varied from year to year, with drought being a crucial determinant of O(3) responsiveness. Regarding adult individuals of a late-successional tree species, empirical proof is provided first time in relation to recent modelling predictions that enhanced ground-level O(3) can substantially mitigate the C sequestration of forests in view of climate change.

  10. Age-related changes in protein metabolism of beech (Fagus sylvatica L.) seeds during alleviation of dormancy and in the early stage of germination.

    PubMed

    Ratajczak, Ewelina; Kalemba, Ewa M; Pukacka, Stanislawa

    2015-09-01

    The long-term storage of seeds generally reduces their viability and vigour. The aim of this work was to evaluate the effect of long-term storage on beech (Fagus sylvatica L.) seeds at optimal conditions, over 9 years, on the total and soluble protein levels and activity of proteolytic enzymes, including endopeptidases, carboxypeptidases and aminopeptidases, as well as free amino acid levels and protein synthesis, in dry seeds, after imbibition and during cold stratification leading to dormancy release and germination. The same analyses were conducted in parallel on seeds gathered from the same tree in the running growing season and stored under the same conditions for only 3 months. The results showed that germination capacity decreased from 100% in freshly harvested seeds to 75% in seeds stored for 9 years. The levels of total and soluble proteins were highest in freshly harvested seeds and decreased significantly during storage, these proportions were retained during cold stratification and germination of seeds. Significant differences between freshly harvested and stored seeds were observed in the activities of proteolytic enzymes, including endopeptidases, aminopeptidases and carboxypeptidases, and in the levels of free amino acids. The neosynthesis of proteins during dormancy release and in the early stage of seed germination was significantly weaker in stored seeds. These results confirm the importance of protein metabolism for seed viability and the consequences of its reduction during seed ageing.

  11. Variation in photosynthetic performance and hydraulic architecture across European beech (Fagus sylvatica L.) populations supports the case for local adaptation to water stress.

    PubMed

    Aranda, Ismael; Cano, Francisco Javier; Gascó, Antonio; Cochard, Hervé; Nardini, Andrea; Mancha, Jose Antonio; López, Rosana; Sánchez-Gómez, David

    2015-01-01

    The aim of this study was to provide new insights into how intraspecific variability in the response of key functional traits to drought dictates the interplay between gas-exchange parameters and the hydraulic architecture of European beech (Fagus sylvatica L.). Considering the relationships between hydraulic and leaf functional traits, we tested whether local adaptation to water stress occurs in this species. To address these objectives, we conducted a glasshouse experiment in which 2-year-old saplings from six beech populations were subjected to different watering treatments. These populations encompassed central and marginal areas of the range, with variation in macro- and microclimatic water availability. The results highlight subtle but significant differences among populations in their functional response to drought. Interpopulation differences in hydraulic traits suggest that vulnerability to cavitation is higher in populations with higher sensitivity to drought. However, there was no clear relationship between variables related to hydraulic efficiency, such as xylem-specific hydraulic conductivity or stomatal conductance, and those that reflect resistance to xylem cavitation (i.e., Ψ(12), the water potential corresponding to a 12% loss of stem hydraulic conductivity). The results suggest that while a trade-off between photosynthetic capacity at the leaf level and hydraulic function of xylem could be established across populations, it functions independently of the compromise between safety and efficiency of the hydraulic system with regard to water use at the interpopulation level.

  12. Patterns of late spring frost leaf damage and recovery in a European beech (Fagus sylvatica L.) stand in south-eastern Germany based on repeated digital photographs

    NASA Astrophysics Data System (ADS)

    Menzel, Annette; Helm, Raimund; Zang, Christian

    2015-04-01

    The seasonality of woody plants in cold and temperate climates is adapted to the annual course of temperature and photoperiod in order to maximise the length of the active growing season and, at the same time, avoid damages by frost events, especially by late spring frosts. Winter chilling, spring warming and finally photoperiod trigger the timely bud burst of European beech (Fagus sylvatica L.) which as a climax species is quite sensitive to winter frost and also as seedling to late spring frosts. However, due to relatively late and less varying dates of leaf unfolding, damages by late spring frosts should not occur each year. In case of a total loss due to a late frost event, F. sylvatica trees produce a new set of leaves which guarantees survival, but diminishes carbon reserves. With a phenological camera we observed the phenological course of such an extreme event in the Nationalpark Bayerischer Wald in May 2011: Spring leaf unfolding, an almost complete loss of fresh green leaves after the frost event in the night 3rd to 4th May, a subsequent leafless period followed by re-sprouting. We modeled this special leaf development from day 80 to 210, observed as green% from the repeated digital camera pictures, using the Bayesian multiple change point approach recently introduced by Henneken et al. (2013). The results for more than 30 trees predominantly suggested a model with five change points: firstly, start of the season, abrupt ending before the frost event, the loss by the frost event and after a longer period of recovery the second leaf unfolding (St. John's sprout) ending in full leaf maturity. Analyzing the results of these models the following questions were answered (1) how long is the period of recovery till the second green-up? (2) does the temporal course of the second leafing differ from the first one? (3) what are the individual factors influencing damage and recovery? (4) are individuals with early or late bud burst more prone to damage? The five

  13. Throughfall deposition and canopy exchange processes along a vertical gradient within the canopy of beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst).

    PubMed

    Adriaenssens, Sandy; Hansen, Karin; Staelens, Jeroen; Wuyts, Karen; De Schrijver, An; Baeten, Lander; Boeckx, Pascal; Samson, Roeland; Verheyen, Kris

    2012-03-15

    To assess the impact of air pollution on forest ecosystems, the canopy is usually considered as a constant single layer in interaction with the atmosphere and incident rain, which could influence the measurement accuracy. In this study the variation of througfall deposition and derived dry deposition and canopy exchange were studied along a vertical gradient in the canopy of one European beech (Fagus sylvatica L.) tree and two Norway spruce (Picea abies (L.) Karst) trees. Throughfall and net throughfall deposition of all ions other than H(+) increased significantly with canopy depth in the middle and lower canopy of the beech tree and in the whole canopy of the spruce trees. Moreover, throughfall and net throughfall of all ions in the spruce canopy decreased with increasing distance to the trunk. Dry deposition occurred mainly in the upper canopy and was highest during the growing season for H(+), NH(4)(+), NO(3)(-) and highest during the dormant season for Na(+), Cl(-), SO(4)(2-) (beech and spruce) and K(+), Ca(2+) and Mg(2+) (spruce only). Canopy leaching of K(+), Ca(2+) and Mg(2+) was observed at all canopy levels and was higher for the beech tree compared to the spruce trees. Canopy uptake of inorganic nitrogen and H(+) occurred mainly in the upper canopy, although significant canopy uptake was found in the middle canopy as well. Canopy exchange was always higher during the growing season compared to the dormant season. This spatial and temporal variation indicates that biogeochemical deposition models would benefit from a multilayer approach for shade-tolerant tree species such as beech and spruce.

  14. Local adaptations to frost in marginal and central populations of the dominant forest tree Fagus sylvatica L. as affected by temperature and extreme drought in common garden experiments.

    PubMed

    Kreyling, Juergen; Buhk, Constanze; Backhaus, Sabrina; Hallinger, Martin; Huber, Gerhard; Huber, Lukas; Jentsch, Anke; Konnert, Monika; Thiel, Daniel; Wilmking, Martin; Beierkuhnlein, Carl

    2014-03-01

    Local adaptations to environmental conditions are of high ecological importance as they determine distribution ranges and likely affect species responses to climate change. Increased environmental stress (warming, extreme drought) due to climate change in combination with decreased genetic mixing due to isolation may lead to stronger local adaptations of geographically marginal than central populations. We experimentally observed local adaptations of three marginal and four central populations of Fagus sylvaticaL., the dominant native forest tree, to frost over winter and in spring (late frost). We determined frost hardiness of buds and roots by the relative electrolyte leakage in two common garden experiments. The experiment at the cold site included a continuous warming treatment; the experiment at the warm site included a preceding summer drought manipulation. In both experiments, we found evidence for local adaptation to frost, with stronger signs of local adaptation in marginal populations. Winter frost killed many of the potted individuals at the cold site, with higher survival in the warming treatment and in those populations originating from colder environments. However, we found no difference in winter frost tolerance of buds among populations, implying that bud survival was not the main cue for mortality. Bud late frost tolerance in April differed between populations at the warm site, mainly because of phenological differences in bud break. Increased spring frost tolerance of plants which had experienced drought stress in the preceding summer could also be explained by shifts in phenology. Stronger local adaptations to climate in geographically marginal than central populations imply the potential for adaptation to climate at range edges. In times of climate change, however, it needs to be tested whether locally adapted populations at range margins can successfully adapt further to changing conditions.

  15. Acclimation of fine root respiration to soil warming involves starch deposition in very fine and fine roots: a case study in Fagus sylvatica saplings.

    PubMed

    Di Iorio, Antonino; Giacomuzzi, Valentino; Chiatante, Donato

    2016-03-01

    Root activities in terms of respiration and non-structural carbohydrates (NSC) storage and mobilization have been suggested as major physiological roles in fine root lifespan. As more frequent heat waves and drought periods within the next decades are expected, to what extent does thermal acclimation in fine roots represent a mechanism to cope with such upcoming climatic conditions? In this study, the possible changes in very fine (diameter < 0.5 mm) and fine (0.5-1 mm) root morphology and physiology in terms of respiration rate and NSC [soluble sugars (SS) and starch] concentrations, were investigated on 2-year-old Fagus sylvatica saplings subjected to a simulated long-lasting heat wave event and to co-occurring soil drying. For both very fine and fine roots, soil temperature (ST) resulted inversely correlated with specific root length, respiration rates and SSs concentration, but directly correlated with root mass, root tissue density and starch concentration. In particular, starch concentration increased under 28 °C for successively decreasing under 21 °C ST. These findings showed that thermal acclimation in very fine and fine roots due to 24 days exposure to high ST (∼ 28 °C), induced starch accumulation. Such 'carbon-savings strategy' should bear the maintenance costs associated to the recovery process in case of restored favorable environmental conditions, such as those occurring at the end of a heat wave event. Drought condition seems to affect the fine root vitality much more under moderate than high temperature condition, making the temporary exposure to high ST less threatening to root vitality than expected.

  16. Patterns of late spring frost leaf damage and recovery in a European beech (Fagus sylvatica L.) stand in south-eastern Germany based on repeated digital photographs.

    PubMed

    Menzel, Annette; Helm, Raimund; Zang, Christian

    2015-01-01

    Damage by late spring frost is a risk deciduous trees have to cope with in order to optimize the length of their growing season. The timing of spring phenological development plays a crucial role, not only at the species level, but also at the population and individual level, since fresh new leaves are especially vulnerable. For the pronounced late spring frost in May 2011 in Germany, we studied the individual leaf development of 35 deciduous trees (mainly European beech Fagus sylvatica L.) at a mountainous forest site in the Bayerischer Wald National Park using repeated digital photographs. Analyses of the time series of greenness by a novel Bayesian multiple change point approach mostly revealed five change points which almost perfectly matched the expected break points in leaf development: (i) start of the first greening between day of the year (DOY) 108-119 (mean 113), (ii) end of greening, and (iii) visible frost damage after the frost on the night of May 3rd/4th (DOY 123/124), (iv) re-sprouting 19-38 days after the frost, and (v) full maturity around DOY 178 (166-184) when all beech crowns had fully recovered. Since frost damage was nearly 100%, individual susceptibility did not depend on the timing of first spring leaf unfolding. However, we could identify significant patterns in fitness linked to an earlier start of leaf unfolding. Those individuals that had an earlier start of greening during the first flushing period had a shorter period of recovery and started the second greening earlier. Thus, phenological timing triggered the speed of recovery from such an extreme event. The maximum greenness achieved, however, did not vary with leaf unfolding dates. Two mountain ashes (Sorbus aucuparia L.) were not affected by the low temperatures of -5°C. Time series analysis of webcam pictures can thus improve process-based knowledge and provide valuable insights into the link between phenological variation, late spring frost damage, and recovery within one stand.

  17. Effect of Forest Management of Picea abies and Fagus sylvatica with Different Types of Felling on Carbon and Economic Balances in the Czech Republic

    NASA Astrophysics Data System (ADS)

    Plch, Radek; Pulkrab, Karel; Bukáček, Jan; Sloup, Roman; Cudlín, Pavel

    2016-10-01

    The selection of the most sustainable forest management under given site conditions needs suitable criteria and indicators. For this purpose, carbon and economic balance assessment, completed with environmental impact computation using the Life Cycle Assessment (LCA) were used. The aim of this study was to compare forestry operations and wood production of selected forest stands with different i) tree species composition (Norway spruce - Picea abies and European beech - Fagus sylvatica) and ii) type of felling (chainsaw and harvester). Carbon and economic balance methods consist in the comparison of quantified inputs (fossil fuels, electricity, used machinery, fertilizers, etc., converted into emission units of carbon in Mg of C- CO2-eq. or EUR) with quantified outputs (biomass production in Mg of carbon or EUR). In this contribution, similar forest stands (“forest site complexes”) in the 4th forest vegetation zone (in the Czech Republic approximately 400-700 m above sea-level) were selected. Forestry operations were divided into 5 main stages: i) seedling production, ii) stand establishment and pruning, iii) thinning and final cutting, iv) skidding, and v) secondary timber transport and modelled for one rotation period of timber production (ca. 100 years). The differences between Norway spruce and European beech forest stands in the carbon efficiency were relatively small while higher differences were achieved in the economic efficiency (forest stands with Norway spruce had a higher economic efficiency). Concerning the comparison of different types of felling in Norway spruce forest stands, the harvester use proved to induce significantly higher environmental impacts (emission of carbon) and lower economic costs. The comparison of forestry operation stages showed that the main part of carbon emissions, originating from fuel production and combustion, is connected with a thinning and final cutting, skidding and secondary timber transport in relations to

  18. Within-Population Genetic Structure in Beech (Fagus sylvatica L.) Stands Characterized by Different Disturbance Histories: Does Forest Management Simplify Population Substructure?

    PubMed Central

    Piotti, Andrea; Leonardi, Stefano; Heuertz, Myriam; Buiteveld, Joukje; Geburek, Thomas; Gerber, Sophie; Kramer, Koen; Vettori, Cristina; Vendramin, Giovanni Giuseppe

    2013-01-01

    The fine-scale assessment of both spatially and non-spatially distributed genetic variation is crucial to preserve forest genetic resources through appropriate forest management. Cryptic within-population genetic structure may be more common than previously thought in forest tree populations, which has strong implications for the potential of forests to adapt to environmental change. The present study was aimed at comparing within-population genetic structure in European beech (Fagus sylvatica L.) plots experiencing different disturbance levels. Five plot pairs made up by disturbed and undisturbed plots having the same biogeographic history were sampled throughout Europe. Overall, 1298 individuals were analyzed using four highly polymorphic nuclear microsatellite markers (SSRs). Bayesian clustering within plots identified 3 to 11 genetic clusters (within-plot θST ranged from 0.025 to 0.124). The proportion of within-population genetic variation due to genetic substructuring (FCluPlot = 0.067) was higher than the differentiation among the 10 plots (FPlotTot = 0.045). Focusing on the comparison between managed and unmanaged plots, disturbance mostly explains differences in the complexity of within-population genetic structure, determining a reduction of the number of genetic clusters present in a standardized area. Our results show that: i) genetic substructuring needs to be investigated when studying the within-population genetic structure in forest tree populations, and ii) indices describing subtle characteristics of the within-population genetic structure are good candidates for providing early signals of the consequences of forest management, and of disturbance events in general. PMID:24039930

  19. Ectomycorrhizal Communities on the Roots of Two Beech (Fagus sylvatica) Populations from Contrasting Climates Differ in Nitrogen Acquisition in a Common Environment

    PubMed Central

    Leberecht, Martin; Dannenmann, Michael; Gschwendtner, Silvia; Bilela, Silvija; Meier, Rudolf; Simon, Judy; Rennenberg, Heinz; Schloter, Michael

    2015-01-01

    Beech (Fagus sylvatica), a dominant forest species in Central Europe, competes for nitrogen with soil microbes and suffers from N limitation under dry conditions. We hypothesized that ectomycorrhizal communities and the free-living rhizosphere microbes from beech trees from sites with two contrasting climatic conditions exhibit differences in N acquisition that contribute to differences in host N uptake and are related to differences in host belowground carbon allocation. To test these hypotheses, young trees from the natural regeneration of two genetically similar populations, one from dryer conditions (located in an area with a southwest exposure [SW trees]) and the other from a cooler, moist climate (located in an area with a northeast exposure [NE trees]), were transplanted into a homogeneous substrate in the same environment and labeled with 13CO2 and 15NH4+. Free-living rhizosphere microbes were characterized by marker genes for the N cycle, but no differences between the rhizospheres of SW or NE trees were found. Lower 15N enrichment was found in the ectomycorrhizal communities of the NE tree communities than the SW tree communities, whereas no significant differences in 15N enrichment were observed for nonmycorrhizal root tips of SW and NE trees. Neither the ectomycorrhizal communities nor the nonmycorrhizal root tips originating from NE and SW trees showed differences in 13C signatures. Because the level of 15N accumulation in fine roots and the amount transferred to leaves were lower in NE trees than SW trees, our data support the suggestion that the ectomycorrhizal community influences N transfer to its host and demonstrate that the fungal community from the dry condition was more efficient in N acquisition when environmental constraints were relieved. These findings highlight the importance of adapted ectomycorrhizal communities for forest nutrition in a changing climate. PMID:26092464

  20. Investigating the European beech (Fagus sylvatica L.) leaf characteristics along the vertical canopy profile: leaf structure, photosynthetic capacity, light energy dissipation and photoprotection mechanisms.

    PubMed

    Scartazza, Andrea; Di Baccio, Daniela; Bertolotto, Pierangelo; Gavrichkova, Olga; Matteucci, Giorgio

    2016-09-01

    Forest functionality and productivity are directly related to canopy light interception and can be affected by potential damage from high irradiance. However, the mechanisms by which leaves adapt to the variable light environments along the multilayer canopy profile are still poorly known. We explored the leaf morphophysiological and metabolic responses to the natural light gradient in a pure European beech (Fagus sylvatica L.) forest at three different canopy heights (top, middle and bottom). Structural adjustment through light-dependent modifications in leaf mass per area was the reason for most of the variations in photosynthetic capacity. The different leaf morphology along the canopy influenced nitrogen (N) partitioning, water- and photosynthetic N-use efficiency, chlorophyll (Chl) fluorescence and quali-quantitative contents of photosynthetic pigments. The Chl a to Chl b ratio and the pool of xanthophyll-cycle pigments (VAZ) increased at the highest irradiance, as well as lutein and β-carotene. The total pool of ascorbate and phenols was higher in leaves of the top and middle canopy layers when compared with the bottom layer, where the ascorbate peroxidase was relatively more activated. The non-photochemical quenching was strongly and positively related to the VAZ/(Chl a + b) ratio, while Chl a/Chl b was related to the photochemical efficiency of photosystem II. Along the multilayer canopy profile, the high energy dissipation capacity of leaves was correlated to an elevated redox potential of antioxidants. The middle layer gave the most relevant contribution to leaf area index and carboxylation capacity of the canopy. In conclusion, a complex interplay among structural, physiological and biochemical traits drives the dynamic leaf acclimation to the natural gradients of variable light environments along the tree canopy profile. The relevant differences observed in leaf traits within the canopy positions of the beech forest should be considered for

  1. The production, localization and spreading of reactive oxygen species contributes to the low vitality of long-term stored common beech (Fagus sylvatica L.) seeds.

    PubMed

    Ratajczak, Ewelina; Małecka, Arleta; Bagniewska-Zadworna, Agnieszka; Kalemba, Ewa Marzena

    2015-02-01

    The common beech (Fagus sylvatica L.) is propagated by seeds, but the seed set is irregular with five to ten years in between crops. It is therefore necessary to store the seeds. However, beech seeds lose germinability during long-term storage. In this study, beech seeds were stored at -10°C under controlled conditions for 2, 5, 8, 11 and 13 years. Our results show that beech seeds lose germinability during storage in proportion to the duration of storage. The decrease in germinability correlated with increased electrolyte leakage and accumulation of superoxide anion radicals, hydrogen peroxide and hydroxyl radicals. Furthermore, a strong positive correlation was observed among the releases of superoxide anion radicals, hydrogen peroxide and hydroxyl radicals. In situ localization showed that superoxide anion radicals and hydrogen peroxide were first detectable in root cap cells. When the seed storage time was extended, the reactive oxygen species fluorescence expanded to more areas of the radicle, reaching the root apical meristem. A storage time-dependent decrease in catalase activity, observed in both embryonic axes and cotyledons, was also positively correlated with germinability. DNA fragmentation was observed in beech seeds during storage and occurred predominantly in embryonic axes stored for 5 years and more. Altogether, these results suggest that the loss of germinability in beech seeds during long-term storage depends on several factors, including strong of reactive oxygen species accumulation accompanied by reduced catalase activity as well as membrane injury and DNA alternations, which may be aging-related and ROS-derived. We suggest that the accumulating reactive oxygen species that spread to the root apical meristem are key factors that affect seed germinability after long-term storage.

  2. Ground-level ozone differentially affects nitrogen acquisition and allocation in mature European beech (Fagus sylvatica) and Norway spruce (Picea abies) trees.

    PubMed

    Weigt, R B; Häberle, K H; Millard, P; Metzger, U; Ritter, W; Blaschke, H; Göttlein, A; Matyssek, R

    2012-10-01

    Impacts of elevated ground-level ozone (O(3)) on nitrogen (N) uptake and allocation were studied on mature European beech (Fagus sylvatica L.) and Norway spruce (Picea abies [L.] Karst.) in a forest stand, hypothesizing that: (i) chronically elevated O(3) limits nutrient uptake, and (ii) beech responds more sensitively to elevated O(3) than spruce, as previously found for juvenile trees. Tree canopies were exposed to twice-ambient O(3) concentrations (2 × O(3)) by a free-air fumigation system, with trees under ambient O(3) serving as control. After 5 years of O(3) fumigation, (15)NH(4)(15)NO(3) was applied to soil, and concentrations of newly acquired N (N(labelled)) and total N (N(total)) in plant compartments and soil measured. Under 2 × O(3), N(labelled) and N(total) were increased in the bulk soil and tended to be lower in fine and coarse roots of both species across the soil horizons, supporting hypothesis (i). N(labelled) was reduced in beech foliage by up to 60%, and by up to 50% in buds under 2 × O(3). Similarly, N(labelled) in stem bark and phloem was reduced. No such reduction was observed in spruce, reflecting a stronger effect on N acquisition in beech in accordance with hypothesis (ii). In spruce, 2 × O(3) tended to favour allocation of new N to foliage. N(labelled) in beech foliage correlated with cumulative seasonal transpiration, indicating impaired N acquisition was probably caused by reduced stomatal conductance and, hence, water transport under elevated O(3). Stimulated fine root growth under 2 × O(3) with a possible increase of below-ground N sink strength may also have accounted for lowered N allocation to above-ground organs. Reduced N uptake and altered allocation may enhance the use of stored N for growth, possibly affecting long-term stand nutrition.

  3. Does reduced precipitation trigger physiological and morphological drought adaptations in European beech (Fagus sylvatica L.)? Comparing provenances across a precipitation gradient.

    PubMed

    Knutzen, Florian; Meier, Ina Christin; Leuschner, Christoph

    2015-09-01

    Global warming and associated decreases in summer rainfall may threaten tree vitality and forest productivity in many regions of the temperate zone in the future. One option for forestry to reduce the risk of failure is to plant genotypes which combine high productivity with drought tolerance. Growth experiments with provenances from different climates indicate that drought exposure can trigger adaptive drought responses in temperate trees, but it is not well known whether and to what extent regional precipitation reduction can increase the drought resistance of a species. We conducted a common garden growth experiment with five European beech (Fagus sylvatica L.) populations from a limited region with pronounced precipitation heterogeneity (816-544 mm year(-1)), where phylogenetically related provenances grew under small to large water deficits. We grew saplings of the five provenances at four soil moisture levels (dry to moist) and measured ∼30 morphological (leaf and root properties, root : shoot ratio), physiological (leaf water status parameters, leaf conductance) and growth-related traits (above- and belowground productivity) with the aim to examine provenance differences in the drought response of morphological and physiological traits and to relate the responsiveness to precipitation at origin. Physiological traits were more strongly influenced by provenance (one-third of the studied traits), while structural traits were primarily affected by water availability in the experiment (two-thirds of the traits). The modulus of leaf tissue elasticity ϵ reached much higher values late in summer in plants from moist origins resulting in more rapid turgor loss and a higher risk of hydraulic failure upon drought. While experimental water shortage affected the majority of morphological and productivity-related traits in the five provenances, most parameters related to leaf water status were insensitive to water shortage. Thus, plant morphology, and root

  4. Age-related variation in carbon allocation at tree and stand scales in beech (Fagus sylvatica L.) and sessile oak (Quercus petraea (Matt.) Liebl.) using a chronosequence approach.

    PubMed

    Genet, H; Bréda, N; Dufrêne, E

    2010-02-01

    Two types of physiological mechanisms can contribute to growth decline with age: (i) the mechanisms leading to the reduction of carbon assimilation (input) and (ii) those leading to modification of the resource economy. Surprisingly, the processes relating to carbon allocation have been little investigated as compared to research on the processes governing carbon assimilation. The objective of this paper was thus to test the hypothesis that growth decrease related to age is accompanied by changes in carbon allocation to the benefit of storage and reproductive functions in two contrasting broad-leaved species: beech (Fagus sylvatica L.) and sessile oak (Quercus petraea (Matt.) Liebl.). Age-related changes in carbon allocation were studied using a chronosequence approach. Chronosequences, each consisting of several even-aged stands ranging from 14 to 175 years old for beech and from 30 to 134 years old for sessile oak, were divided into five or six age classes. In this study, carbon allocations to growth, storage and reproduction were defined as the relative amount of carbon invested in biomass increment, carbohydrate increment and seed production, respectively. Tree-ring width and allometric relationships were used to assess biomass increment at the tree and stand scales. Below-ground biomass was assessed using a specific allometric relationship between root:shoot ratio and age, established from the literature review. Seasonal variations of carbohydrate concentrations were used to assess carbon allocation to storage. Reproduction effort was quantified for beech stands by collecting seed and cupule production. Age-related flagging of biomass productivity was assessed at the tree and stand scales, and carbohydrate quantities in trees increased with age for both species. Seed and cupule production increased with stand age in beech from 56 gC m(-)(2) year(-1) at 30 years old to 129 gC m(-2) year(-1) at 138 years old. In beech, carbon allocation to storage and

  5. Patterns of late spring frost leaf damage and recovery in a European beech (Fagus sylvatica L.) stand in south-eastern Germany based on repeated digital photographs

    PubMed Central

    Menzel, Annette; Helm, Raimund; Zang, Christian

    2015-01-01

    Damage by late spring frost is a risk deciduous trees have to cope with in order to optimize the length of their growing season. The timing of spring phenological development plays a crucial role, not only at the species level, but also at the population and individual level, since fresh new leaves are especially vulnerable. For the pronounced late spring frost in May 2011 in Germany, we studied the individual leaf development of 35 deciduous trees (mainly European beech Fagus sylvatica L.) at a mountainous forest site in the Bayerischer Wald National Park using repeated digital photographs. Analyses of the time series of greenness by a novel Bayesian multiple change point approach mostly revealed five change points which almost perfectly matched the expected break points in leaf development: (i) start of the first greening between day of the year (DOY) 108–119 (mean 113), (ii) end of greening, and (iii) visible frost damage after the frost on the night of May 3rd/4th (DOY 123/124), (iv) re-sprouting 19–38 days after the frost, and (v) full maturity around DOY 178 (166–184) when all beech crowns had fully recovered. Since frost damage was nearly 100%, individual susceptibility did not depend on the timing of first spring leaf unfolding. However, we could identify significant patterns in fitness linked to an earlier start of leaf unfolding. Those individuals that had an earlier start of greening during the first flushing period had a shorter period of recovery and started the second greening earlier. Thus, phenological timing triggered the speed of recovery from such an extreme event. The maximum greenness achieved, however, did not vary with leaf unfolding dates. Two mountain ashes (Sorbus aucuparia L.) were not affected by the low temperatures of -5°C. Time series analysis of webcam pictures can thus improve process-based knowledge and provide valuable insights into the link between phenological variation, late spring frost damage, and recovery within one

  6. The effect of carbohydrate accumulation and nitrogen deficiency on feedback regulation of photosynthesis in beech (Fagus sylvatica) under elevated CO2 concentration

    NASA Astrophysics Data System (ADS)

    Klem, K.; Urban, O.; Holub, P.; Rajsnerova, P.

    2012-04-01

    One of the main manifestations of global change is an increase in atmospheric CO2 concentration. Elevated concentration of CO2 has stimulating effect on plant photosynthesis and consequently also on the productivity. Long-term studies, however, show that this effect is progressively reduced due to feedback regulation of photosynthesis. The main causes of this phenomenon are considered as two factors: i) increased biomass production consumes a larger amount of nitrogen from the soil and this leads to progressive nitrogen limitation of photosynthesis, particularly at the level of the enzyme Rubisco, ii) the sink capacity is genetically limited and elevated CO2 concentration leads to increased accumulation of carbohydtrates (mainly sucrose, which is the main transport form of assimilates) in leaves. Increased concentrations of carbohydrates leads to a feedback regulation of photosynthesis by both, long-term feedback regulation of synthesis of the enzyme Rubisco, and also due to reduced capacity to produce ATP in the chloroplasts. However, mechanisms for interactive effects of nitrogen and accumulation of non-structural carbohydrates are still not well understood. Using 3-year-old Fagus sylvatica seedlings we have explored the interactive effects of nitrogen nutrition and sink capacity manipulation (sucrose feeding) on the dynamics of accumulation of non-structural carbohydrates and changes in photosynthetic parameters under ambient (385 μmol (CO2) mol-1) and elevated (700 μmol(CO2) mol-1) CO2 concentration. Sink manipulation by sucrose feeding led to a continuous increase of non-structural carbohydrates in leaves, which was higher in nitrogen fertilized seedlings. The accumulation of non-structural carbohydrates was also slightly stimulated by elevated CO2 concentration. Exponential decay (p <0.01) was observed in CO2 assimilation rate and stomatal conductance when the content of non-structural carbohydrates increased. However, this relationship was modified by the

  7. Unraveling carbohydrate transport mechanisms in young beech trees (Fagus sylvatica f. purpurea) by 13CO2 efflux measurements from stem and soil

    NASA Astrophysics Data System (ADS)

    Thoms, Ronny; Muhr, Jan; Keitel, Claudia; Kayler, Zachary; Gavrichkova, Olga; Köhler, Michael; Gessler, Arthur; Gleixner, Gerd

    2016-04-01

    Transport mechanisms of soluble carbohydrates and diurnal CO2 efflux from tree stems and surrounding soil are well studied. However, the effect of transport carbohydrates on respiration and their interaction with storage processes is largely unknown. Therefore, we performed a set of 13CO2 pulse labeling experiments on young trees of European beech (Fagus sylvatica f. purpurea). We labeled the whole tree crowns in a closed transparent plastic chamber with 99% 13CO2 for 30 min. In one experiment, only a single branch was labeled and removed 36 hours after labeling. In all experiments, we continuously measured the 13CO2 efflux from stem, branch and soil and sampled leaf and stem material every 3 h for 2 days, followed by a daily sampling of leaves in the successive 5 days. The compound specific δ 13C value of extracted soluble carbohydrates from leaf and stem material was measured by high-performance liquid chromatography linked with an isotope ratio mass spectrometer (HPLC-IRMS). The 13CO2 signal from soil respiration occurred only few hours after labeling indicating a very high transport rate of carbohydrates from leaf to roots and to the rhizosphere. The label was continuously depleted within the next 5 days. In contrast, we observed a remarkable oscillating pattern of 13CO2 efflux from the stem with maximum 13CO2 enrichment at noon and minima at night time. This oscillation suggests that enriched carbohydrates are respired during the day, whereas in the night the enriched sugars are not respired. The observed oscillation in stem 13CO2 enrichment remained unchanged even when only single branches were labelled and cut right afterwards. Thus, storage and conversion of carbohydrates only occurred within the stem. The δ13C patterns of extracted soluble carbohydrates showed, that a transformation of transitory starch to carbohydrates and vice versa was no driver of the oscillating 13CO2 efflux from the stem. Carbohydrates might have been transported in the phloem to

  8. Interaction Effect between Elevated CO2 and Fertilization on Biomass, Gas Exchange and C/N Ratio of European Beech (Fagus sylvatica L.)

    PubMed Central

    Lotfiomran, Neda; Köhl, Michael; Fromm, Jörg

    2016-01-01

    The effects of elevated CO2 and interaction effects between elevated CO2 and nutrient supplies on growth and the C/N ratio of European beech (Fagus sylvatica L.) saplings were studied. One-year-old beech saplings were grown in a greenhouse at ambient (385 ppm) and elevated CO2 (770 ppm/950 ppm), with or without fertilization for two growing seasons. In this study, emphasis is placed on the combined fertilization including phosphorus, potassium and nitrogen with two level of elevated CO2. The fertilized plants grown under elevated CO2 had the highest net leaf photosynthesis rate (Ac). The saplings grown under elevated CO2 had a significantly lower stomatal conductance (gs) than saplings grown under ambient air. No interaction effect was found between elevated CO2 and fertilization on Ac. A interaction effect between CO2 and fertilization, as well as between date and fertilization and between date and CO2 was detected on gs. Leaf chlorophyll content index (CCI) and leaf nitrogen content were strongly positively correlated to each other and both of them decreased under elevated CO2. At the end of both growing seasons, stem dry weight was greater under elevated CO2 and root dry weight was not affected by different treatments. No interaction effect was detected between elevated CO2 and nutrient supplies on the dry weight of different plant tissues (stems and roots). However, elevated CO2 caused a significant decrease in the nitrogen content of plant tissues. Nitrogen reduction in the leaves under elevated CO2 was about 10% and distinctly higher than in the stem and root. The interaction effect of elevated CO2 and fertilization on C/N ratio in plants tissues was significant. The results led to the conclusion that photosynthesis and the C/N ratio increased while stomatal conductance and leaf nitrogen content decreased under elevated CO2 and nutrient-limited conditions. In general, under nutrient-limited conditions, the plant responses to elevated CO2 were decreased. PMID

  9. O3 flux-related responsiveness of photosynthesis, respiration, and stomatal conductance of adult Fagus sylvatica to experimentally enhanced free-air O3 exposure.

    PubMed

    Löw, M; Häberle, K-H; Warren, C R; Matyssek, R

    2007-03-01

    Knowledge of responses of photosynthesis, respiration, and stomatal conductance to cumulative ozone uptake (COU) is still scarce, and this is particularly the case for adult trees. The effect of ozone (O(3)) exposure on trees was examined with 60-year-old beech trees (FAGUS SYLVATICA) at a forest site of southern Germany. Trees were exposed to the ambient O(3) regime (1 x O(3)) or an experimentally elevated twice-ambient O(3) regime (2 x O(3)). The elevated 2 x O (3) regime was provided by means of a free-air O(3) canopy exposure system. The hypotheses were tested that (1) gas exchange is negatively affected by O(3) and (2) the effects of O(3) are dose-dependent and thus the sizes of differences between treatments are positively related to COU. Gas exchange (light-saturated CO(2) uptake rate A(max), stomatal conductance g (s), maximum rate of carboxylation Vc (max), ribulose-1,5-bisphosphate turnover limited rate of photosynthesis J (max), CO(2) compensation point CP, apparent quantum yield of net CO(2) uptake AQ, carboxylation efficiency CE, day- and nighttime respiration) and chlorophyll fluorescence (electron transfer rate, ETR) were measured IN SITU on attached sun and shade leaves. Measurements were made periodically throughout the growing seasons of 2003 (an exceptionally dry year) and 2004 (a year with average rainfall). In 2004 Vc(max), J(max), and CE were lower in trees receiving 2 x O(3) compared with the ambient O(3) regime (1 x O(3)). Treatment differences in Vc (max), J (max), CE were rather small in 2004 (i.e., parameter levels were lower by 10 - 30 % in 2 x O(3) than 1 x O(3)) and not significant in 2003. In 2004 COU was positively correlated with the difference between treatments in A (max), g (s), and ETR (i.e., consistent with the dose-dependence of O(3)'s deleterious effects). However, in 2003, differences in A(max), g (s), and ETR between the two O(3) regimes were smaller at the end of the dry summer 2003 (i.e., when COU was greatest). The

  10. Visualizing carbon and nitrogen transfer in the tripartite symbiosis of Fagus sylvatica, ectomycorrhizal fungi and soil microorganisms using NanoSIMS

    NASA Astrophysics Data System (ADS)

    Mayerhofer, Werner; Dietrich, Marlies; Schintlmeister, Arno; Gabriel, Raphael; Gorka, Stefan; Wiesenbauer, Julia; Martin, Victoria; Schweiger, Peter; Reipert, Siegfried; Weidinger, Marieluise; Richter, Andreas; Woebken, Dagmar; Kaiser, Christina

    2016-04-01

    Translocation of recently photoassimilated plant carbon (C) into soil via root exudates or mycorrhizal fungi is key to understand global carbon cycling. Plants support symbiotic fungi and soil microorganisms with recent photosynthates to get access to essential elements, such as nitrogen (N) and phosphorus. While a 'reciprocal reward strategy' (plants trade C in exchange for nutrients from the fungus) has been shown for certain types of mycorrhizal associations, only little is known about the mechanisms of C and N exchange between mycorrhizal fungal hyphae and soil bacteria. Our understanding of the underlying mechanisms is hampered by the fact that C and N transfer between plants, mycorrhizal fungi and soil bacteria takes place at the micrometer scale, which makes it difficult to explore at the macro scale. In this project we intended to analyse carbon and nitrogen flows between roots of beech trees (Fagus sylvatica), their associated ectomycorrhizal fungi and bacterial community. In order to visualize this nutrient flow at a single cell level, we used a stable isotope double labelling (13C and 15N) approach. Young mycorrhizal beech trees were transferred from a forest to split-root boxes, consisting of two compartments separated by a membrane (35 μm mesh size) which was penetrable for hyphae but not for plant roots. After trees and mycorrhizal fungi were allowed to grow for one year in these boxes, 15N-labelled nitrogen solution was added only to the root-free compartment to allow labelled nitrogen supply only through the fungal network. 13C- labelled carbon was applied by exposing the plants to a 13CO2 gas atmosphere for 8 hours. Spatial distribution of the isotopic label was visualised at the microscale in cross sections of mycorrhizal root-tips (the plant/mycorrhizal fungi interface) and within and on the surface of external mycorrhizal hyphae (the fungi/soil bacteria interface) using nanoscale secondary ion mass spectrometry (NanoSIMS). Corresponding

  11. Carbon assimilation, translocation and respiration in Fagus sylvatica and Abies alba stands measured by gas exchange and isotopic techniques during two contrasting climatic years

    NASA Astrophysics Data System (ADS)

    Gavrichkova, Olga; Scartazza, Andrea; Zampedri, Roberto; Cavagna, Mauro; Sottocornola, Matteo; Matteucci, Giorgio; Brugnoli, Enrico

    2014-05-01

    Global warming is tremendously influencing the climate of mountain areas through constantly rising temperatures and changes in local hydrological cycle. Increase of precipitation extremes, seasonal shifts of rainfall regime, heat waves are becoming more and more frequent events here. Vulnerability and plasticity of the local individual tree species under changing climate has still to be evaluated under field conditions. Two consecutive years, 2012 and 2013 were quite distinct in the climatic conditions during the plant growing season. Summer 2012 was characterized by a prolonged summer drought with almost no precipitation in central Italy from the end of May up to the end of August. The situation was aggravated by a very dry winter during this year. Mean annual temperatures in 2012 were 2oC higher in respect to the temperatures measured in the last 10 years. Conversely, year 2013 was milder with occasional rain events also during the summer months and temperatures close to the average values. In the Alpine zone the difference between two years were less pronounced with 2012 being slightly warmer than average and 2013 was characterized by unusually abundant spring precipitations. Taking advantage of these two contrasting years, we have monitored a functional response of one deciduous and one coniferous mountain forest stands growing in different mountain climate zones to variations in the local climate. The first, a deciduous European beech (Fagus sylvatica) forest, is located in the Appennine region of Italy at 1700 m height (Collelongo site, AQ) and characterized by a Mountain-Mediterranean climate. The second is a mixed forest dominated by Silver fir (Abies alba) which was chosen as a target species for our study. The site is located at 1350m height in the south-eastern Alps (Lavarone, TN) and is characterized by a mountain temperate climate. Sampling of plant material and point flux measurements were performed in the beginning, middle and the end of the growing

  12. Seasonal dynamics in the stable carbon isotope composition δ¹³C from non-leafy branch, trunk and coarse root CO₂ efflux of adult deciduous (Fagus sylvatica) and evergreen (Picea abies) trees.

    PubMed

    Kuptz, Daniel; Matyssek, Rainer; Grams, Thorsten E E

    2011-03-01

    Respiration is a substantial driver of carbon (C) flux in forest ecosystems and stable C isotopes provide an excellent tool for its investigation. We studied seasonal dynamics in δ¹³C of CO₂ efflux (δ¹³C(E)) from non-leafy branches, upper and lower trunks and coarse roots of adult trees, comparing deciduous Fagus sylvatica (European beech) with evergreen Picea abies (Norway spruce). In both species, we observed strong and similar seasonal dynamics in the δ¹³C(E) of above-ground plant components, whereas δ¹³C(E) of coarse roots was rather stable. During summer, δ¹³C(E) of trunks was about -28.2‰ (Beech) and -26.8‰ (Spruce). During winter dormancy, δ¹³C(E) increased by 5.6-9.1‰. The observed dynamics are likely related to a switch from growth to starch accumulation during fall and remobilization of starch, low TCA cycle activity and accumulation of malate by PEPc during winter. The seasonal δ¹³C(E) pattern of branches of Beech and upper trunks of Spruce was less variable, probably because these organs were additionally supplied by winter photosynthesis. In view of our results and pervious studies, we conclude that the pronounced increases in δ¹³C(E) of trunks during the winter results from interrupted access to recent photosynthates.

  13. Seasonal patterns of carbon allocation to respiratory pools in 60-yr-old deciduous (Fagus sylvatica) and evergreen (Picea abies) trees assessed via whole-tree stable carbon isotope labeling.

    PubMed

    Kuptz, Daniel; Fleischmann, Frank; Matyssek, Rainer; Grams, Thorsten E E

    2011-07-01

    • The CO(2) efflux of adult trees is supplied by recent photosynthates and carbon (C) stores. The extent to which these C pools contribute to growth and maintenance respiration (R(G) and R(M), respectively) remains obscure. • Recent photosynthates of adult beech (Fagus sylvatica) and spruce (Picea abies) trees were labeled by exposing whole-tree canopies to (13) C-depleted CO(2). Label was applied three times during the year (in spring, early summer and late summer) and changes in the stable C isotope composition (δ(13) C) of trunk and coarse-root CO(2) efflux were quantified. • Seasonal patterns in C translocation rate (CTR) and fractional contribution of label to CO(2) efflux (F(Label-Max)) were found. CTR was fastest during early summer. In beech, F(Label-Max) was lowest in spring and peaked in trunks during late summer (0.6 ± 0.1, mean ± SE), whereas no trend was observed in coarse roots. No seasonal dynamics in F(Label-Max) were found in spruce. • During spring, the R(G) of beech trunks was largely supplied by C stores. Recent photosynthates supplied growth in early summer and refilled C stores in late summer. In spruce, CO(2) efflux was constantly supplied by a mixture of stored (c. 75%) and recent (c. 25%) C. The hypothesis that R(G) is exclusively supplied by recent photosynthates was rejected for both species.

  14. Effects of Elevated Atmospheric CO2 on Microbial Community Structure at the Plant-Soil Interface of Young Beech Trees (Fagus sylvatica L.) Grown at Two Sites with Contrasting Climatic Conditions.

    PubMed

    Gschwendtner, Silvia; Leberecht, Martin; Engel, Marion; Kublik, Susanne; Dannenmann, Michael; Polle, Andrea; Schloter, Michael

    2015-05-01

    Soil microbial community responses to elevated atmospheric CO2 concentrations (eCO2) occur mainly indirectly via CO2-induced plant growth stimulation leading to quantitative as well as qualitative changes in rhizodeposition and plant litter. In order to gain insight into short-term, site-specific effects of eCO2 on the microbial community structure at the plant-soil interface, young beech trees (Fagus sylvatica L.) from two opposing mountainous slopes with contrasting climatic conditions were incubated under ambient (360 ppm) CO2 concentrations in a greenhouse. One week before harvest, half of the trees were incubated for 2 days under eCO2 (1,100 ppm) conditions. Shifts in the microbial community structure in the adhering soil as well as in the root rhizosphere complex (RRC) were investigated via TRFLP and 454 pyrosequencing based on 16S ribosomal RNA (rRNA) genes. Multivariate analysis of the community profiles showed clear changes of microbial community structure between plants grown under ambient and elevated CO2 mainly in RRC. Both TRFLP and 454 pyrosequencing showed a significant decrease in the microbial diversity and evenness as a response of CO2 enrichment. While Alphaproteobacteria dominated by Rhizobiales decreased at eCO2, Betaproteobacteria, mainly Burkholderiales, remained unaffected. In contrast, Gammaproteobacteria and Deltaproteobacteria, predominated by Pseudomonadales and Myxococcales, respectively, increased at eCO2. Members of the order Actinomycetales increased, whereas within the phylum Acidobacteria subgroup Gp1 decreased, and the subgroups Gp4 and Gp6 increased under atmospheric CO2 enrichment. Moreover, Planctomycetes and Firmicutes, mainly members of Bacilli, increased under eCO2. Overall, the effect intensity of eCO2 on soil microbial communities was dependent on the distance to the roots. This effect was consistent for all trees under investigation; a site-specific effect of eCO2 in response to the origin of the trees was not observed.

  15. Fate of recently fixed carbon in European beech (Fagus sylvatica) saplings during drought and subsequent recovery.

    PubMed

    Zang, Ulrich; Goisser, Michael; Grams, Thorsten E E; Häberle, Karl-Heinz; Matyssek, Rainer; Matzner, Egbert; Borken, Werner

    2014-01-01

    Drought reduces the carbon (C) assimilation of trees and decouples aboveground from belowground carbon fluxes, but little is known about the response of drought-stressed trees to rewetting. This study aims to assess dynamics and patterns of C allocation in beech saplings under dry and rewetted soil conditions. In October 2010, 5-year-old beech saplings from a forest site were transplanted into 20 l pots. In 2011, the saplings were subjected to different levels of soil drought ranging from non-limiting water supply (control) to severe water limitation with soil water potentials of less than -1.5 MPa. As a physiologically relevant measure of drought, the cumulated soil water potential (i.e., drought stress dose (DSD)) was calculated for the growing season. In late August, the saplings were transferred into a climate chamber and pulse-labeled with (13)C-depleted CO2 (δ(13)C of -47‰). Isotopic signatures in leaf and soil respiration were repeatedly measured. Five days after soil rewetting, a second label was applied using 99 atom% (13)CO2. After another 12 days, the fate of assimilated C in each sapling was assessed by calculating the (13)C mass balance. Photosynthesis decreased by 60% in saplings under severe drought. The mean residence time (MRT) of recent assimilates in leaf respiration was more than three times longer than under non-limited conditions and was positively correlated to DSD. Also, the appearance of the label in soil respiration was delayed. Within 5 days after rewetting, photosynthesis, MRT of recent assimilates in leaf respiration and appearance of the label in soil respiration recovered fully. Despite the fast recovery, less label was recovered in the biomass of the previously drought-stressed plants, which also allocated less C to the root compartment (45 vs 64% in the control). We conclude that beech saplings quickly recover from extreme soil drought, although transitional after-effects prevail in C allocation, possibly due to repair-driven respiratory processes.

  16. Fagus sylvatica trunk epicormics in relation to primary and secondary growth

    PubMed Central

    Colin, F.; Sanjines, A.; Fortin, M.; Bontemps, J.-D.; Nicolini, E.

    2012-01-01

    Background and Aims European beech epicormics have received far less attention than epicormics of other species, especially sessile oak. However, previous work on beech has demonstrated that there is a negative effect of radial growth on trunk sprouting, while more recent investigations on sessile oak proved a strong positive influence of the presence of epicormics. The aims of this study were, first, to make a general quantification of the epicormics present along beech stems and, secondly, to test the effects of both radial growth and epicormic frequency on sprouting. Methods In order to test the effect of radial growth, ten forked individuals were sampled, with a dominant and a dominated fork of almost equal length for every individual. To test the effects of primary growth and epicormic frequency, on the last 17 annual shoots of each fork arm, the number of axillary buds, shoot length, ring width profiles, epicormic shoots and other epicormics were carefully recorded. Key Results The distribution of annual shoot length, radial growth profiles and parallel frequencies of all epicormics are presented. The latter frequencies were parallel to the annual shoot lengths, nearly equivalent for both arms of each tree, and radial growth profiles included very narrow rings in the lowest annual shoots and even missing rings in the dominated arms alone. The location of the latent buds and the epicormics was mainly at branch base, while epicormic shoots, bud clusters and spheroblasts were present mainly in the lowest annual shoots investigated. Using a zero-inflated mixed model, sprouting was shown to depend positively on epicormic frequency and negatively on radial growth. Conclusions Support for a trade-off between cambial activity and sprouting is put forward. Sprouting mainly depends on the frequency of epicormics. Between- and within-tree variability of the epicormic composition in a given species may thus have fundamental and applied implications. PMID:22887022

  17. Competition for nitrogen sources between European beech (Fagus sylvatica) and sycamore maple (Acer pseudoplatanus) seedlings.

    PubMed

    Simon, J; Waldhecker, P; Brüggemann, N; Rennenberg, H

    2010-05-01

    To investigate the short-term consequences of direct competition between beech and sycamore maple on root N uptake and N composition, mycorrhizal seedlings of both tree species were incubated for 4 days (i.e. beech only, sycamore maple only or both together) in an artificial nutrient solution with low N availability. On the fourth day, N uptake experiments were conducted to study the effects of competition on inorganic and organic N uptake. For this purpose, multiple N sources were applied with a single label. Furthermore, fine roots were sampled and analysed for total amino acids, soluble protein, total nitrogen, nitrate and ammonium content. Our results clearly show that both tree species were able to use inorganic and organic N sources. Uptake of inorganic and organic N by beech roots was negatively affected in the presence of the competing tree species. In contrast, the presence of beech stimulated inorganic N uptake by sycamore maple roots. Both the negative effect of sycamore maple on N uptake of beech and the positive effect of beech on N uptake of sycamore maple led to an increase in root soluble protein in beech, despite an overall decrease in total N concentration. Thus, beech compensated for the negative effects of the tree competitor on N uptake by incorporating less N into structural N components, but otherwise exhibited the same strategy as the competitor, namely, enhancing soluble protein levels in roots when grown under competition. It is speculated that enhanced enzyme activities of so far unknown nature are required in beech as a defence response to inter-specific competition.

  18. Competition for nitrogen between Fagus sylvatica and Acer pseudoplatanus seedlings depends on soil nitrogen availability.

    PubMed

    Li, Xiuyuan; Rennenberg, Heinz; Simon, Judy

    2015-01-01

    Competition for nitrogen (N), particularly in resource-limited habitats, might be avoided by different N acquisition strategies of plants. In our study, we investigated whether slow-growing European beech and fast-growing sycamore maple seedlings avoid competition for growth-limiting N by different N uptake patterns and the potential alteration by soil N availability in a microcosm experiment. We quantified growth and biomass indices, (15)N uptake capacity and N pools in the fine roots. Overall, growth indices, N acquisition and N pools in the fine roots were influenced by species-specific competition depending on soil N availability. With inter-specific competition, growth of sycamore maple reduced regardless of soil N supply, whereas beech only showed reduced growth when N was limited. Both species responded to inter-specific competition by alteration of N pools in the fine roots; however, sycamore maple showed a stronger response compared to beech for almost all N pools in roots, except for structural N at low soil N availability. Beech generally preferred organic N acquisition while sycamore maple took up more inorganic N. Furthermore, with inter-specific competition, beech had an enhanced organic N uptake capacity, while in sycamore maple inorganic N uptake capacity was impaired by the presence of beech. Although sycamore maple could tolerate the suboptimal conditions at the cost of reduced growth, our study indicates its reduced competitive ability for N compared to beech.

  19. Contrasting carbon allocation responses of juvenile European beech (Fagus sylvatica) and Norway spruce (Picea abies) to competition and ozone.

    PubMed

    Ritter, Wilma; Lehmeier, Christoph Andreas; Winkler, Jana Barbro; Matyssek, Rainer; Edgar Grams, Thorsten Erhard

    2015-01-01

    Allocation of recent photoassimilates of juvenile beech and spruce in response to twice-ambient ozone (2 × O(3)) and plant competition (i.e. intra vs. inter-specific) was examined in a phytotron study. To this end, we employed continuous (13)CO(2)/(12)CO(2) labeling during late summer and pursued tracer kinetics in CO(2) released from stems. In beech, allocation of recent photoassimilates to stems was significantly lowered under 2 × O(3) and increased in spruce when grown in mixed culture. As total tree biomass was not yet affected by the treatments, C allocation reflected incipient tree responses providing the mechanistic basis for biomass partitioning as observed in longer experiments. Compartmental modeling characterized functional properties of substrate pools supplying respiratory C demand. Respiration of spruce appeared to be exclusively supplied by recent photoassimilates. In beech, older C, putatively located in stem parenchyma cells, was a major source of respiratory substrate, reflecting the fundamental anatomical disparity between angiosperm beech and gymnosperm spruce.

  20. Tree Age Effects on Fine Root Biomass and Morphology over Chronosequences of Fagus sylvatica, Quercus robur and Alnus glutinosa Stands

    PubMed Central

    Jagodzinski, Andrzej M.; Ziółkowski, Jędrzej; Warnkowska, Aleksandra; Prais, Hubert

    2016-01-01

    There are few data on fine root biomass and morphology change in relation to stand age. Based on chronosequences for beech (9–140 years old), oak (11–140 years) and alder (4–76 years old) we aimed to examine how stand age affects fine root biomass and morphology. Soil cores from depths of 0–15 cm and 16–30 cm were used for the study. In contrast to previously published studies that suggested that maximum fine root biomass is reached at the canopy closure stage of stand development, we found almost linear increases of fine root biomass over stand age within the chronosequences. We did not observe any fine root biomass peak in the canopy closure stage. However, we found statistically significant increases of mean fine root biomass for the average individual tree in each chronosequence. Mean fine root biomass (0–30 cm) differed significantly among tree species chronosequences studied and was 4.32 Mg ha-1, 3.71 Mg ha-1 and 1.53 Mg ha-1, for beech, oak and alder stands, respectively. The highest fine root length, surface area, volume and number of fine root tips (0–30 cm soil depth), expressed on a stand area basis, occurred in beech stands, with medium values for oak stands and the lowest for alder stands. In the alder chronosequence all these values increased with stand age, in the beech chronosequence they decreased and in the oak chronosequence they increased until ca. 50 year old stands and then reached steady-state. Our study has proved statistically significant negative relationships between stand age and specific root length (SRL) in 0–30 cm soil depth for beech and oak chronosequences. Mean SRLs for each chronosequence were not significantly different among species for either soil depth studied. The results of this study indicate high fine root plasticity. Although only limited datasets are currently available, these data have provided valuable insight into fine root biomass and morphology of beech, oak and alder stands. PMID:26859755

  1. Tree Age Effects on Fine Root Biomass and Morphology over Chronosequences of Fagus sylvatica, Quercus robur and Alnus glutinosa Stands.

    PubMed

    Jagodzinski, Andrzej M; Ziółkowski, Jędrzej; Warnkowska, Aleksandra; Prais, Hubert

    2016-01-01

    There are few data on fine root biomass and morphology change in relation to stand age. Based on chronosequences for beech (9-140 years old), oak (11-140 years) and alder (4-76 years old) we aimed to examine how stand age affects fine root biomass and morphology. Soil cores from depths of 0-15 cm and 16-30 cm were used for the study. In contrast to previously published studies that suggested that maximum fine root biomass is reached at the canopy closure stage of stand development, we found almost linear increases of fine root biomass over stand age within the chronosequences. We did not observe any fine root biomass peak in the canopy closure stage. However, we found statistically significant increases of mean fine root biomass for the average individual tree in each chronosequence. Mean fine root biomass (0-30 cm) differed significantly among tree species chronosequences studied and was 4.32 Mg ha(-1), 3.71 Mg ha(-1) and 1.53 Mg ha(-1), for beech, oak and alder stands, respectively. The highest fine root length, surface area, volume and number of fine root tips (0-30 cm soil depth), expressed on a stand area basis, occurred in beech stands, with medium values for oak stands and the lowest for alder stands. In the alder chronosequence all these values increased with stand age, in the beech chronosequence they decreased and in the oak chronosequence they increased until ca. 50 year old stands and then reached steady-state. Our study has proved statistically significant negative relationships between stand age and specific root length (SRL) in 0-30 cm soil depth for beech and oak chronosequences. Mean SRLs for each chronosequence were not significantly different among species for either soil depth studied. The results of this study indicate high fine root plasticity. Although only limited datasets are currently available, these data have provided valuable insight into fine root biomass and morphology of beech, oak and alder stands.

  2. Differential radial growth patterns between beech (Fagus sylvatica L.) and oak (Quercus robur L.) on periodically waterlogged soils.

    PubMed

    Scharnweber, Tobias; Manthey, Michael; Wilmking, Martin

    2013-04-01

    Climate scenarios for northern Central Europe project rising temperatures and increasing frequency and intensity of droughts but also a shift in precipitation pattern with more humid winters. This in turn may result in soil waterlogging during the following spring, leading to increasing stress for trees growing on hydric sites. The influence of waterlogging on growth of common beech and pedunculate oak has been studied intensively on seedlings under experimental conditions. However, the question remains whether results of these studies can be transferred to mature trees growing under natural conditions. To test this, we investigated general growth patterns and climate-growth relationships in four mature stands of beech and oak growing on hydromorphic soils (Stagnosols) in northeast Germany using dendrochronological methods. Our results confirmed the expected tolerance of oak to strong water-level fluctuations. Neither extremely wet conditions during spring nor summer droughts significantly affected its radial growth. Oak growth responded positively to warmer temperatures during previous year October and March of the current year of ring formation. Contrary to our expectations, also beech showed relatively low sensitivity to periods of high soil water saturation. Instead, summer drought turned out to be the main climatic factor influencing ring width of beech even under the specific periodically wet soil conditions of our study. This became evident from general climate-growth correlations over the last century as well as from discontinuous (pointer year) analysis with summer drought being significantly correlated to the occurrence of growth depressions. As ring width of the two species is affected by differing climate parameters, species-specific chronologies show no coherence in high-frequency variations even for trees growing in close proximity. We assume differences in rooting depth as the main reason for the differing growth patterns and climate correlations of the two species under study. Our results indicate that under the projected future climate scenarios, beech may suffer from increasing drought stress even on hydromorphic soils. Oak might be able to maintain a sufficient hydraulic status during summer droughts by reaching water in deeper soil strata with its root system. Wet phases with waterlogged soil conditions during spring or summer appear to have only a little direct influence on radial growth of both species.

  3. Differences in Soil Fungal Communities between European Beech (Fagus sylvatica L.) Dominated Forests Are Related to Soil and Understory Vegetation

    PubMed Central

    Schöning, Ingo; Boch, Steffen; Gawlich, Melanie; Schnabel, Beatrix; Fischer, Markus; Buscot, François

    2012-01-01

    Fungi are important members of soil microbial communities with a crucial role in biogeochemical processes. Although soil fungi are known to be highly diverse, little is known about factors influencing variations in their diversity and community structure among forests dominated by the same tree species but spread over different regions and under different managements. We analyzed the soil fungal diversity and community composition of managed and unmanaged European beech dominated forests located in three German regions, the Schwäbische Alb in Southwestern, the Hainich-Dün in Central and the Schorfheide Chorin in the Northeastern Germany, using internal transcribed spacer (ITS) rDNA pyrotag sequencing. Multiple sequence quality filtering followed by sequence data normalization revealed 1655 fungal operational taxonomic units. Further analysis based on 722 abundant fungal OTUs revealed the phylum Basidiomycota to be dominant (54%) and its community to comprise 71.4% of ectomycorrhizal taxa. Fungal community structure differed significantly (p≤0.001) among the three regions and was characterized by non-random fungal OTUs co-occurrence. Soil parameters, herbaceous understory vegetation, and litter cover affected fungal community structure. However, within each study region we found no difference in fungal community structure between management types. Our results also showed region specific significant correlation patterns between the dominant ectomycorrhizal fungal genera. This suggests that soil fungal communities are region-specific but nevertheless composed of functionally diverse and complementary taxa. PMID:23094057

  4. Impact of elevated CO2 concentration on dynamics of leaf photosynthesis in Fagus sylvatica is modulated by sky conditions.

    PubMed

    Urban, Otmar; Klem, Karel; Holišová, Petra; Šigut, Ladislav; Šprtová, Mirka; Teslová-Navrátilová, Petra; Zitová, Martina; Špunda, Vladimír; Marek, Michal V; Grace, John

    2014-02-01

    It has been suggested that atmospheric CO2 concentration and frequency of cloud cover will increase in future. It remains unclear, however, how elevated CO2 influences photosynthesis under complex clear versus cloudy sky conditions. Accordingly, diurnal changes in photosynthetic responses among beech trees grown at ambient (AC) and doubled (EC) CO2 concentrations were studied under contrasting sky conditions. EC stimulated the daily sum of fixed CO2 and light use efficiency under clear sky. Meanwhile, both these parameters were reduced under cloudy sky as compared with AC treatment. Reduction in photosynthesis rate under cloudy sky was particularly associated with EC-stimulated, xanthophyll-dependent thermal dissipation of absorbed light energy. Under clear sky, a pronounced afternoon depression of CO2 assimilation rate was found in sun-adapted leaves under EC compared with AC conditions. This was caused in particular by stomata closure mediated by vapour pressure deficit.

  5. Patterns of molecular and morphological differentiation in Fagus (Fagaceae): phylogenetic implications.

    PubMed

    Denk, Thomas; Grimm, Guido W; Hemleben, Vera

    2005-06-01

    To study phylogenetic relationships among species of Fagus, the internal transcribed spacer regions ITS1 and ITS2 of the nuclear ribosomal DNA and morphological data were analyzed. Both molecular and morphologically based phylogenies suggest that Eurasian species of Fagus subgenus Fagus are basal to the North American Fagus grandifolia. The subgenus Fagus is a paraphyletic group basal to three East Asian species forming the subgenus Engleriana. Due to a considerably large amount of DNA polymorphism, relationships among basal species of Fagus could not be entirely resolved when analyzing ITS sequences with standard methods. Morphological trees helped to resolve more clearly relationships within the subgenus Fagus. The East Asian F. hayatae is suggested to be basal to the rest of the genus. This hypothesis is further supported by distinctive patterns of nucleotide variability found for ITS regions, allowing for basic and derived types to be distinguished. The high degree of ITS polymorphism within Fagus can be explained by (1) the complex evolutionary behavior of this marker, (2) the stenoecious ecological characteristic of Fagus with respect to its continuous geographic range throughout much of the Cenozoic, and (3) the absence of major radiations into further habitats as occurred in other Fagaceae.

  6. Belowground effects of enhanced tropospheric ozone and drought in a beech/spruce forest (Fagus sylvatica L./Picea abies [L.] Karst).

    PubMed

    Nikolova, Petia S; Andersen, Christian P; Blaschke, Helmut; Matyssek, Rainer; Häberle, Karl-Heinz

    2010-04-01

    The effects of experimentally elevated O(3) on soil respiration rates, standing fine-root biomass, fine-root production and delta(13)C signature of newly produced fine roots were investigated in an adult European beech/Norway spruce forest in Germany during two subsequent years with contrasting rainfall patterns. During humid 2002, soil respiration rate was enhanced under elevated O(3) under beech and spruce, and was related to O(3)-stimulated fine-root production only in beech. During dry 2003, the stimulating effect of O(3) on soil respiration rate vanished under spruce, which was correlated with decreased fine-root production in spruce under drought, irrespective of the O(3) regime. delta(13)C signature of newly formed fine-roots was consistent with the differing g(s) of beech and spruce, and indicated stomatal limitation by O(3) in beech and by drought in spruce. Our study showed that drought can override the stimulating O(3) effects on fine-root dynamics and soil respiration in mature beech and spruce forests.

  7. Impacts of a water stress followed by an early frost event on beech (Fagus sylvatica L.) susceptibility to Scolytine ambrosia beetles - Research strategy and first results

    NASA Astrophysics Data System (ADS)

    La Spina, Sylvie; de Cannière, Charles; Molenberg, Jean-Marc; Vincke, Caroline; Deman, Déborah; Grégoire, Jean-Claude

    2010-05-01

    Climate change tends to induce more frequent abiotic and biotic extreme events, having large impacts on tree vitality. Weakened trees are then more susceptible to secondary insect outbreaks, as it happened in Belgium in the early 2000s: after an early frost event, secondary Scolytine ambrosia beetles attacks were observed on beech trees. In this study, we test if a combination of stress, i.e. a soil water deficit preceding an early frost, could render trees more attractive to beetles. An experimental study was set in autumn 2008. Two parcels of a beech forest were covered with plastic tents to induce a water stress by rain interception. The parcels were surrounded by 2-meters depth trenches to avoid water supply by streaming. Soil water content and different indicators of tree water use (sap flow, predawn leaf water potential, tree radial growth) were followed. In autumn 2010, artificial frost injuries will be inflicted to trees using dry ice. Trees attractivity for Scolytine insects, and the success of insect colonization will then be studied. The poster will focus on experiment setting and first results (impacts of soil water deficit on trees).

  8. Whole-tree seasonal nitrogen uptake and partitioning in adult Fagus sylvatica L. and Picea abies L. [Karst.] trees exposed to elevated ground-level ozone.

    PubMed

    Weigt, R B; Häberle, K H; Rötzer, T; Matyssek, R

    2015-01-01

    The effect of long-term exposure of twice-ambient O(3) (2 × O(3)) on whole-tree nitrogen (N) uptake and partitioning of adult beech and spruce was studied in a mixed forest stand, SE-Germany. N uptake as (15)N tracer and N pools were calculated using N concentrations and biomass of tree compartments. Whole-tree N uptake tended to be lower under 2 × O(3) in both species compared to trees under ambient O(3) (1 × O(3)). Internal partitioning in beech showed significantly higher allocation of new N to roots, with mycorrhizal root tips and fine roots together receiving about 17% of new N (2 × O(3)) versus 7% (1 × O(3)). Conversely, in spruce, N allocation to roots was decreased under 2 × O(3). These contrasting effects on belowground N partitioning and pool sizes, being largely consistent with the pattern of N concentrations, suggest enhanced N demand and consumption of stored N with higher relevance for tree-internal N cycling in beech than in spruce.

  9. The role of the organic layer for phosphorus nutrition of young beech trees (Fagus sylvatica L.) at two sites differing in soil Phosphorus availability

    NASA Astrophysics Data System (ADS)

    Hauenstein, Simon

    2016-04-01

    Simon Hauenstein1, Thomas Pütz2, and Yvonne Oelmann1, 1 Geoecology, Department of Geosciences, University of Tübingen, Tübingen, Germany 2 Agrosphere (IBG-3), Forschungszentrum Jülich, Jülich, Germany The accumulation of an organic layer in forests is linked to the ratio between litterfall rates and decomposition rates with decomposition rates being decelerated due to acidification and associated nutrient depletion with proceeding ecosystem development. Nevertheless, the nutrient pool in the organic layer might still represent an important source for Phosphorus (P) nutrition of forests on nutrient-poor soils. Our objective was to assess the importance of the organic layer to P nutrition of young beech trees at two sites differing in soil P availability. We established a mesocosm experiment including plants and soil from a Phosphorus depleted forest site on a Haplic Podzol in Lüss and a Phosphorus rich forest site on a Eutric Cambisol in Bad Brückenau either with or without the organic layer. After 1 year under outdoor conditions, we applied 33P to the pots. After 0h, 24h, 48h, 96h, 192h, 528h we destructively harvested the young beech trees (separated into leaves, branches, stems) and sampled the organic layer and mineral soil of the pots. In each soil horizon we measured concentrations of resin-extractable P, plant available P fractions and total P. We extracted the xylem sap of the whole 2-year-old trees by means of scholander pressure bomb. 33P activity was measured for every compartment in soil and plant. The applied 33P was recovered mainly in the organic layer in Lüss, whereas it was evenly distributed among organic and mineral horizons in pots of Bad Brückenau soil. Comparing pots with and without an organic layer, the specific 33P activity differed by 323% between pots with and without an organic layer present in the Lüss soil. For both sites, the presence of the organic layer increased 33P activity in xylem sap compared to the treatment without by 104% in Bad Brückenau and 700% in Lüss. Whereas the existence of an organic layer did not influence the total 33P activity in plant tissue in pots from the site Bad Brückenau over 528h, a strong increase of 155 kBq/g DM was recorded for the site Lüss. Therefore, the key role of the organic layer for plant P nutrition on a P depleted site like Lüss was reflected in the increased P uptake rates (xylem sap) and increased accumulation of P in plant tissue comparing the presence and absence of an organic layerIn conclusion, our results prove the more efficient cycling of P in the organic layers in Lüss as opposed to Bad Brückenau corroborating the hypothesized P recycling and P acquiring strategy in Lüss and Bad Brückenau, respectively.

  10. Below-ground effects of enhanced tropospheric ozone and drought in a beech/spruce forest (Fagus sylvatica L. / Picea abies [L.] Karst)

    EPA Science Inventory

    The effects of experimentally elevated O3 on soil respiration rates, standing fine-root biomass, fine-root production and δ13C signature of newly produced fine roots were investigated in an adult European beech/Norway spruce forest in Germany during two subsequent years with cont...

  11. 1H, 13C and 15N resonance assignments and second structure information of Fag s 1: Fagales allergen from Fagus sylvatica.

    PubMed

    Moraes, A H; Asam, C; Batista, A; Almeida, F C L; Wallner, M; Ferreira, F; Valente, A P

    2016-04-01

    Fagales allergens belonging to the Bet v 1 family account responsible for the majority of spring pollinosis in the temperate climate zones in the Northern hemisphere. Among them, Fag s 1 from beech pollen is an important trigger of Fagales pollen associated allergic reactions. The protein shares high similarity with birch pollen Bet v 1, the best-characterized member of this allergen family. Of note, recent work on Bet v 1 and its homologues found in Fagales pollen demonstrated that not all allergenic members of this family have the capacity to induce allergic sensitization. Fag s 1 was shown to bind pre-existing IgE antibodies most likely primarily directed against other members of this multi-allergen family. Therefore, it is especially interesting to compare the structures of Bet v 1-like pollen allergens, which have the potential to induce allergic sensitization with allergens that are mainly cross-reactive. This in the end will help to identify allergy eliciting molecular pattern on Bet v 1-like allergens. In this work, we report the (1)H, (15)N and (13)C NMR assignment of beech pollen Fag s 1 as well as the secondary structure information based on backbone chemical shifts.

  12. The phylogeography of Fagus hayatae (Fagaceae): genetic isolation among populations.

    PubMed

    Ying, Ling-Xiao; Zhang, Ting-Ting; Chiu, Ching-An; Chen, Tze-Ying; Luo, Shu-Jin; Chen, Xiao-Yong; Shen, Ze-Hao

    2016-05-01

    The beech species Fagus hayatae is an important relict tree species in subtropical China, whose biogeographical patterns may reflect floral responses to climate change in this region during the Quaternary. Previous studies have revealed phylogeography for three of the four Fagus species in China, but study on F. hayatae, the most sparsely distributed of these species, is still lacking. Here, molecular methods based on eight simple sequence repeat (SSR) loci of nuclear DNA (nDNA) and three chloroplast DNA (cpDNA) sequences were applied for analyses of genetic diversity and structure in 375 samples from 14 F. hayatae populations across its whole range. Both nDNA and cpDNA indicated a high level of genetic diversity in this species. Significant fixation indexes and departures from the Hardy-Weinberg equilibrium, with a genetic differentiation parameter of R st of 0.233, were detected in nDNA SSR loci among populations, especially those on Taiwan Island, indicating strong geographic partitioning. The populations were classified into two clusters, without a prominent signal of isolation-by-distance. For the 15 haplotypes detected in the cpDNA sequence fragments, there was a high genetic differentiation parameter (G st = 0.712) among populations. A high G st of 0.829 was also detected outside but not within the Sichuan Basin. Consistent with other Fagus species in China, no recent population expansion was detected from tests of neutrality and mismatch distribution analysis. Overall, genetic isolation with limited gene flow was prominent for this species and significant phylogeographic structures existed across its range except for those inside the Sichuan Basin. Our study suggested long-term geographic isolation in F. hayatae with limited population admixture and the existence of multiple refugia in the mountainous regions of the Sichuan Basin and southeast China during the Quaternary. These results may provide useful information critical for the conservation of F

  13. Mangifera sylvatica (Wild Mango): A new cocoa butter alternative

    PubMed Central

    Akhter, Sayma; McDonald, Morag A.; Marriott, Ray

    2016-01-01

    Cocoa butter is the pure butter extracted from cocoa beans and is a major ingredient in the chocolate industry. Global production of cocoa is in decline due to crop failure, diseases and ageing plantations, leading to price fluctuations and the necessity for the industry to find high quality cocoa butter alternatives. This study explored the potential of a wild mango (Mangifera sylvatica), an underutilised fruit in south-east Asia, as a new Cocoa Butter Alternative (CBA). Analyses showed that wild mango butter has a light coloured fat with a similar fatty acid profile (palmitic, stearic and oleic acid) and triglyceride profile (POP, SOS and POS) to cocoa butter. Thermal and physical properties are also similar to cocoa butter. Additionally, wild mango butter comprises 65% SOS (1, 3-distearoyl-2-oleoyl-glycerol) which indicates potential to become a Cocoa Butter Improver (an enhancement of CBA). It is concluded that these attractive properties of wild mango could be prompted by a coalition of policy makers, foresters, food industries and horticulturists to promote more widespread cultivation of this wild fruit species to realise the market opportunity. PMID:27555345

  14. Mangifera sylvatica (Wild Mango): A new cocoa butter alternative

    NASA Astrophysics Data System (ADS)

    Akhter, Sayma; McDonald, Morag A.; Marriott, Ray

    2016-08-01

    Cocoa butter is the pure butter extracted from cocoa beans and is a major ingredient in the chocolate industry. Global production of cocoa is in decline due to crop failure, diseases and ageing plantations, leading to price fluctuations and the necessity for the industry to find high quality cocoa butter alternatives. This study explored the potential of a wild mango (Mangifera sylvatica), an underutilised fruit in south-east Asia, as a new Cocoa Butter Alternative (CBA). Analyses showed that wild mango butter has a light coloured fat with a similar fatty acid profile (palmitic, stearic and oleic acid) and triglyceride profile (POP, SOS and POS) to cocoa butter. Thermal and physical properties are also similar to cocoa butter. Additionally, wild mango butter comprises 65% SOS (1, 3-distearoyl-2-oleoyl-glycerol) which indicates potential to become a Cocoa Butter Improver (an enhancement of CBA). It is concluded that these attractive properties of wild mango could be prompted by a coalition of policy makers, foresters, food industries and horticulturists to promote more widespread cultivation of this wild fruit species to realise the market opportunity.

  15. Mangifera sylvatica (Wild Mango): A new cocoa butter alternative.

    PubMed

    Akhter, Sayma; McDonald, Morag A; Marriott, Ray

    2016-08-24

    Cocoa butter is the pure butter extracted from cocoa beans and is a major ingredient in the chocolate industry. Global production of cocoa is in decline due to crop failure, diseases and ageing plantations, leading to price fluctuations and the necessity for the industry to find high quality cocoa butter alternatives. This study explored the potential of a wild mango (Mangifera sylvatica), an underutilised fruit in south-east Asia, as a new Cocoa Butter Alternative (CBA). Analyses showed that wild mango butter has a light coloured fat with a similar fatty acid profile (palmitic, stearic and oleic acid) and triglyceride profile (POP, SOS and POS) to cocoa butter. Thermal and physical properties are also similar to cocoa butter. Additionally, wild mango butter comprises 65% SOS (1, 3-distearoyl-2-oleoyl-glycerol) which indicates potential to become a Cocoa Butter Improver (an enhancement of CBA). It is concluded that these attractive properties of wild mango could be prompted by a coalition of policy makers, foresters, food industries and horticulturists to promote more widespread cultivation of this wild fruit species to realise the market opportunity.

  16. The wood frog (Rana sylvatica): a technical conservation assessment

    USGS Publications Warehouse

    Muths, E.; Rittmann, S.; Irwin, J.; Keinath, D.; Scherer, R.

    2005-01-01

    Overall, the wood frog (Rana sylvatica) is ranked G5, secure through most of its range (NatureServe Explorer 2002). However, it is more vulnerable in some states within the USDA Forest Service Region 2: S3 (vulnerable) in Colorado, S2 (imperiled) in Wyoming, and S1 (critically imperiled in South Dakota (NatureServe Explorer 2002); there are no records for wood frogs in Kansas or Nebraska. Primary threats to wood frog populations are habitat fragmentation (loss of area, edge effects, and isolation) and habitat loss due to anthropogenic causes (e.g., wetland draining, grazing) and natural changes as habitat succession occurs. Wood frogs are most conspicuous at breeding sites early in the spring, when snow and ice are often still present at pond margins. They tolerate frezzing and hibernate terrestrially in shallow depressions, under leaf litter, grasses, logs, or rocks (Bagdonas 1968, Bellis 1961a); there are no reports of aquatic hibernation for this species (Licht 1991, Pinder et al. 1992). Wood frogs require semi-permanent and temporary pools of natural origin and adjacent wet meadows, and landscape alterations that shorten the hydroperiod of ponds can result in catastrophic tadpole mortality. Plant communities utilized by wood frogs in the Rocky Mountains are hydric to mesic and include sedge and grass meadows, willow hummocks, aspen groves, lodgepole pine forests, and woodlands with leaf litter and/or herbaceous understory (Maslin 1947, Bellis 1961a, Roberts and Lewin 1979, Haynes and Aird 1981). Wood frogs are likely to disperse into surrounding marsh and woodlands soon after oviposition (Heatwole 1961, Haynes and Aird 1981). In the arly fall, wood frogs begin to seek hibernacula at or just below the ground surface, generally in upland forest habitat (Regosin et al. 2003). Licht (1991) demonstrated shelter-seeking behavior at 1.5 [degrees] C. Once they have concealed themselves for hibernation, wood frogs are very difficult to detecta?|

  17. Effect of acidic precipitation on amphibian breeding in temporary ponds in Pennsylvania. [Rana sylvatica; Ambystoma jeffersonianum

    SciTech Connect

    Freda, J.; Dunson, W.A.

    1985-11-01

    This study assessed the impacts of acid deposition on amphibians breeding in temporary ponds in Pennsylvania by investigating the lowest pH's at which embryos could hatch, the physiological effects of low pH on amphibian larvae, pond chemistry and the influence of rainfall on pond pH, and the effect of pond pH on embryonic survival and local distribution of Ambystoma jeffersonianum and Rana sylvatica. At very low pH's, embryos stopped development soon after exposure. At higher but still lethal pH's, embryos became curled and failed to hatch. Embryos of Ambystoma were able to hatch even though they were curled, but R. sylvatica became trapped and died. Acute exposure to low pH's depressed sodium influx and accelerated sodium efflux, with a net loss of 50% of body sodium resulting in death. Increasing the external calcium concentration extended survival time by slowing the loss of sodium. Chronic exposure to low pH's resulted in reduction in body sodium, but to a lesser degree. R sylvatica tadpoles from a low pH pond had lower body sodium than tadpoles from a nearby high pH pond. Tadpoles from both ponds placed in a low pH pond underwent higher sodium efflux than when placed in the high pH pond. In studying the effect of low environmental pH, A. jeffersonianum was intolerant of low pH and was absent from most acidic ponds. R. sylvatica was tolerant and was found in ponds with the lowest pH. 73 refs., 14 figs., 21 tabs.

  18. Formation of cis-coniferin in cell-free extracts of Fagus grandifolia Ehrh bark

    NASA Technical Reports Server (NTRS)

    Yamamoto, E.; Inciong, E. J.; Davin, L. B.; Lewis, N. G.

    1990-01-01

    American beech (Fagus grandifolia Ehrh) bark exclusively accumulates cis-monolignols and their glucosidic conjugates; no evidence for the accumulation of trans-monolignols has been found. The glucosyltransferase from this source exhibits a very unusual substrate specificity for cis, and not trans, monolignols. This is further evidence that cis monolignols are involved in lignin formation in these plant tissues. Preliminary evidence for the existence of a novel trans-cis monolignol isomerase was obtained, in agreement with our contention that this isomerization is not photochemically mediated.

  19. Growth of Fagus in transition zones of forest and soil on the western slope of Mt. Chokai, northern Japan

    NASA Astrophysics Data System (ADS)

    Kato, S.; Watanabe, M.

    2012-04-01

    A wide transition zone for forest structure is expected to distribute on the gentle slope of western side of Mt. Chokai ,Yamagata prefecture, northern Japan (N39° 05'57", E140°02'55"). The annual mean temperature and total precipitation at summit (2,059 m asl.) are 0.5° C and 3,285mm, respectively. The parent materials of the soils are weathered Andesite associated with non-tephric loess deposits transported from continental China. Representative sites were selected in forests of Quercus mongolica and Fagus crenata to examine characteristics of transition zones of vegetation and soil in the western slope of Mt. Chokai with concern on the growth of Fagus in transition zones. Surveys on vegetation profile and projection diagram of canopy for each site (10-10m plots) were carried out in 7 sites selected along altitudinal sequence on the western slope of Mt. Chokai; Ch1-7: 550-1,100m asl.. Growth rate of Fagus was estimated by the measurement of tree rings from increment core samples. Timber volume of Fagus at each point was calculated based on diameter of breast height; DBH as an indicator of tree biomass. Soil profiles were observed at the above 7 sites and soil samples were collected from each horizon. As for soil analyses, soil pH (H2O, KCl, NaF) values were measured by the glass electrode method in the suspension mixture of soil with a 2.5 times volume of H2O or 1N KCl and 50 times volume of 4% NaF. Pyrophosphate, acid oxalate and dithionite-citrate extractable Al (Alp, Alo, Ald), Fe (Feo, Fed) and Si (Sio, Sid) were measured by ICP-AES. The content of exchangeable Al (AlEX) was obtained by titration of extract with 1N KCl. Sclerotia formed by species of Cenococcum, ectomycorrhizal fungi, were collected for grains of diameter larger than 0.5mm from wet samples. Sclerotia content was obtained by weight (mg g-1 soil). Due to intensive base leaching under extremely high precipitation and the mineralogical properties, Ah and Ae horizons of all profiles had low soil

  20. Growing trees on completed sanitary landfills. [Nyssa sylvatica, Picea abies, Ginkgo biloba

    SciTech Connect

    Leone, I.A.; Gilman, E.F.; Flower, F.B.

    1983-01-01

    A 10-year old completed landfill in New Jersey consisting of 9 m (depth) of refuse covered with 15-25 cm of soil was cleared of debris and vegetation and covered with 30 cm of subsoil and 15-25 cm of topsoil. Nineteen coniferous and broadleaved species were planted on the landfill and on a control site in 1975, and trees were maintained and growth and condition monitored over 4 years. On the basis of shoot length and stem area increase, the most successful of the surviving trees were Nyssa sylvatica, Picea abies and Ginkgo biloba, in decreasing order of tolerance. Tolerance of landfill conditions appeared to be greatest in those species with low water requirements, a slow growth rate, high acid tolerance and a shallow root system. (Refs. 11).

  1. Impacts of weathered tire debris on the development of Rana sylvatica larvae

    USGS Publications Warehouse

    Camponelli, K.M.; Casey, R.E.; Snodgrass, J.W.; Lev, S.M.; Landa, E.R.

    2009-01-01

    Highway runoff has the potential to negatively impact receiving systems including stormwater retention ponds where highway particulate matter can accumulate following runoff events. Tire wear particles, which contain about 1% Zn by mass, make up approximately one-third of the vehicle derived particulates in highway runoff and therefore may serve as a stressor to organisms utilizing retention ponds as habitat. In this study, we focused on the potential contribution of tire debris to Zn accumulation by Rana sylvatica larvae and possible lethal or sublethal impacts resulting from exposure to weathered tire debris during development. Eggs and larvae were exposed to aged sediments (containing either ZnCl2 or tire particulate matter, both providing nominal concentrations of 1000 mg Zn kg-1) through metamorphosis. Water column Zn was elevated in both the ZnCl2 and tire treatments relative to the control treatment, indicating that aging allowed Zn leaching from tire debris to occur. Tissue Zn was also elevated for the ZnCl2 and tire treatments indicating that Zn in the treatments was available for uptake by the amphibians. Exposure to both ZnCl2 and tire treatments increased the time for larvae to complete metamorphosis in comparison with controls. We also observed that the longer the organisms took to complete metamorphosis, the smaller their mass at metamorphosis. Our results indicate that Zn leached from aged tire debris is bioavailable to developing R. sylvatica larvae and that exposure to tire debris amended sediments can result in measurable physiological outcomes to wood frogs that may influence population dynamics. ?? 2008 Elsevier Ltd.

  2. Effects of six chemical deicers on larval wood frogs (Rana sylvatica).

    PubMed

    Harless, Meagan L; Huckins, Casey J; Grant, Jacqualine B; Pypker, Thomas G

    2011-07-01

    Widespread and intensive application of road deicers, primarily road salt (NaCl), in North America threatens water quality and the health of freshwater ecosystems. Intensive use of NaCl can be harmful to sensitive members of freshwater ecosystems such as amphibians. Detection of negative effects of NaCl application has prompted the search for alternative chemical deicers with lower environmental impacts. We conducted a series of 96-h acute toxicity tests to determine the negative sensitivity of larval wood frogs (Rana [Lithobates] sylvatica) to six deicing chemicals: urea (CH(4) N(2) O), sodium chloride (NaCl), magnesium chloride (MgCl(2) ), potassium acetate (CH(3) COOK), calcium chloride (CaCl(2) ), and calcium magnesium acetate (C(8) H(12) CaMgO(8) ). Acetates are sometimes touted as environmentally friendly alternatives to NaCl but have not been examined in enough detail to warrant this designation. When exposed to a range of environmentally realistic concentrations of these chemicals, larvae were least sensitive (i.e., had the lowest mortality rate) to CH(4) N(2) O, NaCl, and MgCl(2) and most sensitive to acetates (C(8) H(12) CaMgO(8) , CH(3) COOK) and CaCl(2) . Our observed median lethal concentration estimates (LC50(96-h) ) for NaCl were over two times higher than values presented in previous studies, which suggests variability in tolerance among R. sylvatica populations. The deicers varied greatly in their toxicity, and further research is warranted to examine the differential effects of this suite of deicers on other species.

  3. Pseudacris triseriata (western chorus frog) and Rana sylvatica (wood frog) chytridiomycosis

    USGS Publications Warehouse

    Rittman, S.E.; Muths, E.; Green, D.E.

    2003-01-01

    The chytrid fungus Batrachochytrium dendrobatidis is a known pathogen of anuran amphibians, and has been correlated with amphibian die-offs worldwide (Daszak et. al. 1999. Emerging Infectious Diseases 5:735-748). In Colorado, B. dendrobatidis has infected Boreal toads (Bufo boreas) (Muths et. al., in review) and has been identified on museum specimens of northern leopard frogs (Rana pipiens) (Carey et. al. 1999. Develop. Comp. Immunol. 23:459-472). We report the first verified case of chytrid fungus in chorus frogs (Pseudacris triseriata) and wood frogs (Rana sylvatica) in the United States. We collected seven P. triseriata, and two adult and two juvenile R. sylvatica in the Kawuneeche Valley in Rocky Mountain National Park (RMNP) during June 2001. These animals were submitted to the National Wildlife Health Center (NWHC) as part of an amphibian health evaluation in RMNP. Chorus frogs were shipped in one container. Wood frog adults and juveniles were shipped in two separate containers. Histological examinations of all chorus frogs and 3 of 4 wood frogs were positive for chytrid fungus infection. The fourth (adult) wood frog was too decomposed for meaningful histology. Histological findings consisted of multifocally mild to diffusely severe infections of the epidermis of the ventrum and hindlimb digital skin. Chytrid thalli were confined to the thickened epidermis (hyperkeratosis), were spherical to oval, and occasional thalli contained characteristic discharge pores or zoospores (Green and Kagarise Sherman 1999. J. Herpetol 35:92-103; Fellers et al. 2001. Copeia 2001:945-953). We cannot confirm that all specimens carried the fungus at collection, because infection may have spread from one individual to all other individuals in each container during transport. Further sampling of amphibians in Kawuneeche Valley is warranted to determine the rate of infection and mortality in these populations.

  4. Long-term growth trajectories in a changing climate: disentangling age from size effects in old Fagus trees from contrasting bioclimates

    NASA Astrophysics Data System (ADS)

    Di Filippo, Alfredo; Piovesan, Gianluca

    2016-04-01

    Understanding the drivers promoting exceptional longevity in trees and how their growth performances vary approaching maximum lifespan still represent intriguing challenges not only for tree biology, but also for modelling the long-term forest ecosystem functioning under a changing environment. Tree growth rate is expected to increase with increasing stem size, but higher risk of hydraulic failure and mortality can affect larger trees under increasingly dry conditions. In turn, very old trees are characterized by slow growth and smaller size, factors able to confer advantages against biotic and abiotic disturbances. Rising evidences that very old trees are negligibly affected by the progressive deterioration of physiological functions associated with age support the idea that size, not age, is the main constrain to tree lifespan, so that negative senescence has been proposed as a frequent phenomenon in trees. Additional empirical knowledge is needed to thoroughly assess how complex, uneven-aged old-growth forests cope under climate change in order to define their role in terrestrial carbon cycle. We used a tree-ring network of 8 European beech (Fagus sylvatica L.) old-growth forests containing several of the oldest crossdated broadleaf trees of the Northern Hemisphere (400-600 years old) to analyse how their growth rates vary along age/size development. We sampled advanced old-growth stands, where canopy tree mortality is naturally occurring, divided among contrasting bioclimatic conditions: eastern Alps and central Apennines (rainy vs. dry summer). To disentangle the long-term effects of size and age on long-term tree growth history, we reconstructed Basal Area Increment (BAI) along size (DBH) development, grouping growth trajectories in different age classes. On average, BAI increased continuously as stem size increased, regardless of bioclimatic region and age class. Old trees grew the slowest and kept increasing BAI trends. In turn, especially on the drier

  5. A slight recovery of soils from Acid Rain over the last three decades is not reflected in the macro nutrition of beech (Fagus sylvatica) at 97 forest stands of the Vienna Woods.

    PubMed

    Berger, Torsten W; Türtscher, Selina; Berger, Pétra; Lindebner, Leopold

    2016-09-01

    Rigorous studies of recovery from soil acidification are rare. Hence, we resampled 97 old-growth beech stands in the Vienna Woods. This study exploits an extensive data set of soil (infiltration zone of stemflow and between trees area at different soil depths) and foliar chemistry from three decades ago. It was hypothesized that declining acidic deposition is reflected in soil and foliar chemistry. Top soil pH within the stemflow area increased significantly by 0.6 units in both H2O and KCl extracts from 1984 to 2012. Exchangeable Ca and Mg increased markedly in the stemflow area and to a lower extent in the top soil of the between trees area. Trends of declining base cations in the lower top soil were probably caused by mobilization of organic S and associated leaching with high amounts of sulfate. Contents of C, N and S decreased markedly in the stemflow area from 1984 to 2012, suggesting that mineralization rates of organic matter increased due to more favorable soil conditions. It is concluded that the top soil will continue to recover from acidic deposition. However, in the between trees areas and especially in deeper soil horizons recovery may be highly delayed. The beech trees of the Vienna Woods showed no sign of recovery from acidification although S deposition levels decreased. Release of historic S even increased foliar S contents. Base cation levels in the foliage declined but are still adequate for beech trees. Increasing N/nutrient ratios over time were considered not the result of marginally higher N foliar contents in 2012 but of diminishing nutrient uptake due to the decrease in ion concentration in soil solution. The mean foliar N/P ratio already increased to the alarming value of 31. Further nutritional imbalances will predispose trees to vitality loss.

  6. A slight recovery of soils from Acid Rain over the last three decades is not reflected in the macro nutrition of beech (Fagus sylvatica) at 97 forest stands of the Vienna Woods✰

    PubMed Central

    Berger, Pétra; Lindebner, Leopold

    2016-01-01

    Rigorous studies of recovery from soil acidification are rare. Hence, we resampled 97 old-growth beech stands in the Vienna Woods. This study exploits an extensive data set of soil (infiltration zone of stemflow and between trees area at different soil depths) and foliar chemistry from three decades ago. It was hypothesized that declining acidic deposition is reflected in soil and foliar chemistry. Top soil pH within the stemflow area increased significantly by 0.6 units in both H2O and KCl extracts from 1984 to 2012. Exchangeable Ca and Mg increased markedly in the stemflow area and to a lower extent in the top soil of the between trees area. Trends of declining base cations in the lower top soil were probably caused by mobilization of organic S and associated leaching with high amounts of sulfate. Contents of C, N and S decreased markedly in the stemflow area from 1984 to 2012, suggesting that mineralization rates of organic matter increased due to more favorable soil conditions. It is concluded that the top soil will continue to recover from acidic deposition. However, in the between trees areas and especially in deeper soil horizons recovery may be highly delayed. The beech trees of the Vienna Woods showed no sign of recovery from acidification although S deposition levels decreased. Release of historic S even increased foliar S contents. Base cation levels in the foliage declined but are still adequate for beech trees. Increasing N/nutrient ratios over time were considered not the result of marginally higher N foliar contents in 2012 but of diminishing nutrient uptake due to the decrease in ion concentration in soil solution. The mean foliar N/P ratio already increased to the alarming value of 31. Further nutritional imbalances will predispose trees to vitality loss. PMID:27344089

  7. Exclusive accumulation of Z-isomers of monolignols and their glucosides in bark of Fagus grandifolia

    NASA Technical Reports Server (NTRS)

    Lewis, N. G.; Inciong, E. J.; Ohashi, H.; Towers, G. H.; Yamamoto, E.

    1988-01-01

    In addition to Z-coniferyl and Z-sinapyl alcohols, bark extracts of Fagus grandifolia also contain significant amounts of the glucosides, Z-coniferin, Z-isoconiferin (previously called faguside) and Z-syringin. The corresponding E-isomers of these glucosides do not accumulate to a detectable level. The accumulation of the Z-isomers suggests that either they are not lignin precursors or that they are reservoirs of monolignols for subsequent lignin biosynthesis; it is not possible to distinguish between these alternatives. The co-occurrence of Z-coniferin and Z-isoconiferin demonstrate that glucosylation of monolignols can occur at either the phenolic or the allylic hydroxyl groups.

  8. Two Lactarius species associated with a relict Fagus grandifolia var. mexicana population in a Mexican montane cloud forest.

    PubMed

    Montoya, L; Haug, I; Bandala, V M

    2010-01-01

    Ectomycorrhizal (EM) fleshy fungi are being monitored in a population of Fagus grandifolia var. mexicana persisting in a montane cloud forest refuge on a volcano in a subtropical region of central Veracruz (eastern Mexico). The population of Fagus studied represents one of the 10 recognized forest fragments still housing this tree genus in Mexico. This is the first attempt to document EM fungi associated with this tree species in Mexico. We present evidence of the ectomycorrhizal symbiosis for Lactarius badiopallescens and L. cinereus with this endemic tree. Species identification of Lactarius on Fagus grandifolia var. mexicana was based on the comparison of DNAsequences (ITS rDNA) of spatiotemporally co-occurring basidiomes and EM root tips. The host of the EM tips was identified by comparison of the large subunit of the ribulose-bisphosphate carboxylase gene (rbcL). The occurrence of Lactarius badiopallescens and L. cinereus populations in the area of study represent the southernmost record known to date of these two species in North America and are new for the Neotropical Lactarius mycota. Descriptions coupled with illustrations of macro- and micromorphological features of basidiomes as well as photographs of ectomycorrhizas are presented.

  9. Enzymatic regulation of seasonal glycogen cycling in the freeze-tolerant wood frog, Rana sylvatica.

    PubMed

    do Amaral, M Clara F; Lee, Richard E; Costanzo, Jon P

    2016-12-01

    Liver glycogen is an important energy store in vertebrates, and in the freeze-tolerant wood frog, Rana sylvatica, this carbohydrate also serves as a major source of the cryoprotectant glucose. We investigated how variation in the levels of the catalytic subunit of protein kinase A (PKAc), glycogen phosphorylase (GP), and glycogen synthase (GS) relates to seasonal glycogen cycling in a temperate (Ohioan) and subarctic (Alaskan) populations of this species. In spring, Ohioan frogs had reduced potential for glycogen synthesis, as evidenced by low GS activity and high PKAc protein levels. In addition, glycogen levels in spring were the lowest of four seasonal samples, as energy input was likely directed towards metabolism and somatic growth during this period. Near-maximal glycogen levels were reached by mid-summer, and remained unchanged in fall and winter, suggesting that glycogenesis was curtailed during this period. Ohioan frogs had a high potential for glycogenolysis and glycogenesis in winter, as evidenced by large glycogen reserves, high levels of GP and GS proteins, and high GS activity, which likely allows for rapid mobilization of cryoprotectant during freezing and replenishing of glycogen reserves during thawing. Alaskan frogs also achieved a near-maximal liver glycogen concentration by summer and displayed high glycogenic and glycogenolytic potential in winter, but, unlike Ohioan frogs, started replenishing their energy reserves early in spring. We conclude that variation in levels of both glycogenolytic and glycogenic enzymes likely happens in response to seasonal changes in energetic strategies and demands, with winter survival being a key component to understanding the regulation of glycogen cycling in this species.

  10. Regulation of SMAD transcription factors during freezing in the freeze tolerant wood frog, Rana sylvatica.

    PubMed

    Aguilar, Oscar A; Hadj-Moussa, Hanane; Storey, Kenneth B

    2016-11-01

    The wood frog, Rana sylvatica, survives sub-zero winter temperatures by undergoing full body freezing for weeks at a time, during which it displays no measurable brain activity, no breathing, and a flat-lined heart. Freezing is a hypometabolic state characterized by a global suppression of gene expression that is elicited in part by transcription factors that coordinate the activation of vital pro-survival pathways. Smad transcription factors respond to TGF-β signalling and are involved in numerous cellular functions from development to stress. Given the identity of genes they regulate, we hypothesized that they may be involved in coordinating gene expression during freezing. Protein expression of Smad1/2/3/4/5 in response to freezing was examined in 24h frozen and 8h thawed wood frog tissues using western immunoblotting, with the determination of subcellular localization in muscle and liver tissues. Transcript levels of smad2, smad4 and downstream genes (serpine1, myostatin, and tsc22d3) were measured by RT-PCR. Tissue-specific responses were observed during freezing where brain, heart, and liver had elevated levels of pSmad3, and skeletal muscle and kidneys had increased levels of pSmad1/5 and pSmad2 during freeze/thaw cycle, while protein and transcript levels remained constant. There were increases in nuclear levels of pSmad2 in muscle and pSmad3 in liver. Transcript levels of serpine1 were induced in heart, muscle, and liver, myostatin in muscle, and tsc22d3 in heart, and liver during freezing. These results suggest a novel freeze-responsive activation of Smad proteins that may play an important role in coordinating pro-survival gene networks necessary for freeze tolerance.

  11. Pathogenesis of Frog Virus 3 ( Ranavirus, Iridoviridae) Infection in Wood Frogs ( Rana sylvatica).

    PubMed

    Forzán, M J; Jones, K M; Ariel, E; Whittington, R J; Wood, J; Markham, R J Frederick; Daoust, P-Y

    2017-01-01

    Wood frogs ( Rana sylvatica) are highly susceptible to infection with Frog virus 3 (FV3, Ranavirus, Iridoviridae), a cause of mass mortality in wild populations. To elucidate the pathogenesis of FV3 infection in wood frogs, 40 wild-caught adults were acclimated to captivity, inoculated orally with a fatal dose of 10(4.43) pfu/frog, and euthanized at 0.25, 0.5, 1, 2, 4, 9, and 14 days postinfection (dpi). Mild lesions occurred sporadically in the skin (petechiae) and bone marrow (necrosis) during the first 2 dpi. Severe lesions occurred 1 to 2 weeks postinfection and consisted of necrosis of medullary and extramedullary hematopoietic tissue, lymphoid tissue in spleen and throughout the body, and epithelium of skin, mucosae, and renal tubules. Viral DNA was first detected (polymerase chain reaction) in liver at 4 dpi; by dpi 9 and 14, all viscera tested (liver, kidney, and spleen), skin, and feces were positive. Immunohistochemistry (IHC) first detected viral antigen in small areas devoid of histologic lesions in the oral mucosa, lung, and colon at 4 dpi; by 9 and 14 dpi, IHC labeling of viral antigen associated with necrosis was found in multiple tissues. Based on IHC staining intensity and lesion severity, the skin, oral, and gastrointestinal epithelium and renal tubular epithelium were important sites of viral replication and shedding, suggesting that direct contact (skin) and fecal-oral contamination are effective routes of transmission and that skin tissue, oral, and cloacal swabs may be appropriate antemortem diagnostic samples in late stages of disease (>1 week postinfection) but poor samples to detect infection in clinically healthy frogs.

  12. Bolete diversity in two relict forests of the Mexican beech (Fagus grandifolia var. mexicana; Fagaceae).

    PubMed

    Rodríguez-Ramírez, Ernesto Ch; Moreno, Claudia E

    2010-05-01

    The current distribution of the endangered Mexican beech [Fagus grandifolia var. mexicana (Martinez) Little] is restricted to relict isolated populations in small remnants of montane cloud forest in northeastern Mexico, and little is known about its associated biota. We sampled bolete diversity in two of these monospecific forests in the state of Hidalgo, Mexico. We compared alpha diversity, including species richness and ensemble structure, and analyzed beta diversity (dissimilarity in species composition) between forests. We found 26 bolete species, five of which are probably new. Species diversity and evenness were similar between forests. Beta diversity was low, and the similarities of bolete samples from within and between forests were not significantly different. These results support the idea that the two forests share a single bolete ensemble with a common history. In contrast, cumulative species richness differed between the forests, implying that factors other than the mere presence of the host species have contributed to shaping the biodiversity of ectomycorrhizal fungi in relict Mexican beech forests.

  13. Delayed fertilization and pollen-tube growth in pistils of Fagus japonica (Fagaceae).

    PubMed

    Sogo, Akiko; Tobe, Hiroshi

    2006-12-01

    In contrast to most angiosperms, in which fertilization occurs 1 or 2 days after pollination, in some plant orders, including the Fagales, fertilization is delayed from 4 days to more than 1 year, raising questions regarding why fertilization is delayed and where and how pollen tubes remain in the pistil during the delay. To answer these questions, we investigated pollen-tube growth in pistils of Fagus japonica (Fagaceae), which are tricarpellate and have six ovules, using light, fluorescence, and scanning electron microscopy. The ovules were immature at the time of pollination and required 5 weeks to become fully developed. During this 5 weeks, pollen tubes grew from the stigma to the embryo sac in association with the development of ovules and intermittently in three steps with two growth-cessation sites, i.e., on the funicle and near the micropyle. The number of pollen tubes was gradually reduced from many to one at the two growth-cessation sites, and fertilization occurred in one ovule that apparently developed earlier than the others in the pistil. Thus, delayed fertilization plays an important role in gametophyte competition and selection leading to nonrandom fertilization. Intermittent pollen-tube growth is also likely widespread in angiosperms because it is known in other Fagales and an unrelated order Garryales.

  14. Intraspecific variation and phylogeographic patterns of Fagus crenata (Fagaceae) mitochondrial DNA.

    PubMed

    Tomaru, N; Takahashi, M; Tsumura, Y; Takahashi, M; Ohba, K

    1998-05-01

    Mitochondrial (mt) DNA variation in Japanese beech, Fagus crenata (Fagaceae), was studied in 17 populations distributed throughout the species' range. Total genomic DNA of samples from single trees representing each of 12 populations were digested with 18 restriction enzymes and hybridized with three probes containing coxI, coxIII, and atpA gene sequences. Thirty-four of the 54 enzyme/probe combinations showed polymorphisms and all the individuals were subsequently analyzed with six combinations of three probes and two enzymes. Restriction fragment length polymorphisms were evident around all three genes, allowing the identification of eight distinct haplotypes. Haplotype diversity within the populations was found to be very low (HS = 0.031), but population differentiation to be much higher (GST = 0.963). The mtDNA variation was strikingly different from allozyme variation (HS = 0.209; GST = 0.039). Gene flow for maternally inherited mtDNA should be restricted to seed dispersal while nuclear gene flow occurs by both seed and pollen dispersal. Therefore, the difference in the variation between mtDNA and allozymes may be largely a result of the much higher rate of gene flow associated with pollen dispersal than with seed dispersal. The mtDNA variation displayed strong geographic structure, which may reflect the species' distribution in the last glacial maximum and subsequent colonization, and probably also reflects intraspecific phylogeography of the species.

  15. Habitat differences influence genetic impacts of human land use on the American beech (Fagus grandifolia).

    PubMed

    Lumibao, Candice Y; McLachlan, Jason S

    2014-01-01

    Natural reforestation after regional forest clearance is a globally common land-use sequence. The genetic recovery of tree populations in these recolonized forests may depend on the biogeographic setting of the landscape, for instance whether they are in the core or in the marginal part of the species' range. Using data from 501 individuals genotyped across 7 microsatellites, we investigated whether regional differences in habitat quality affected the recovery of genetic variation in a wind-pollinated tree species, American beech (Fagus grandifolia) in Massachusetts. We compared populations in forests that were recolonized following agricultural abandonment to those in remnant forests that have only been logged in both central inland and marginal coastal regions. Across all populations in our entire study region, recolonized forests showed limited reduction of genetic diversity as only observed heterozygosity was significantly reduced in these forests (H(O) = 0.520 and 0.590, respectively). Within inland region, this pattern was observed, whereas in the coast, recolonized populations exhibited no reduction in all genetic diversity estimates. However, genetic differentiation among recolonized populations in marginal coastal habitat increased (F(st) logged = 0.072; F(st) secondary = 0.249), with populations showing strong genetic structure, in contrast to inland region. These results indicate that the magnitude of recovery of genetic variation in recolonized populations can vary at different habitats.

  16. Transcript expression of the freeze responsive gene fr10 in Rana sylvatica during freezing, anoxia, dehydration, and development.

    PubMed

    Sullivan, K J; Biggar, K K; Storey, K B

    2015-01-01

    Freeze tolerance is a critical winter survival strategy for the wood frog, Rana sylvatica. In response to freezing, a number of genes are upregulated to facilitate the survival response. This includes fr10, a novel freeze-responsive gene first identified in R. sylvatica. This study analyzes the transcriptional expression of fr10 in seven tissues in response to freezing, anoxia, and dehydration stress, and throughout the Gosner stages of tadpole development. Transcription of fr10 increased overall in response to 24 h of freezing, with significant increases in expression detected in testes, heart, brain, and lung when compared to control tissues. When exposed to anoxia; heart, lung, and kidney tissues experienced a significant increase, while the transcription of fr10 in response to 40% dehydration was found to significantly increase in both heart and brain tissues. An analysis of the transcription of fr10 throughout the development of the wood frog showed a relatively constant expression; with slightly lower transcription levels observed in two of the seven Gosner stages. Based on these results, it is predicted that fr10 has multiple roles depending on the needs and stresses experienced by the wood frog. It has conclusively been shown to act as a cryoprotectant, with possible additional roles in anoxia, dehydration, and development. In the future, it is hoped that further knowledge of the mechanism of action of FR10 will allow for increased stress tolerance in human cells and tissues.

  17. Genetic structure in populations of an ancient woodland sedge, Carex sylvatica Hudson, at a regional and local scale.

    PubMed

    Arens, P; Bijlsma, R-J; van't Westende, W; van Os, B; Smulders, M J M; Vosman, B

    2005-07-01

    Wood sedge (Carex sylvatica) is a well-known ancient woodland species with a long-term persistent seed bank and a caespitose growth habit. All thirteen isolated Carex sylvatica populations in the Dutch Rhine floodplain (including the river branches Waal and IJssel) were mapped in detail and analysed for genetic variation at a large number of AFLP loci and one microsatellite locus. Across all populations, only 40 % of the sampled individuals (n=216) represented a unique genotype. A high number of the studied patches (spatial clusters of tussocks, 2-10 m in diameter) within populations contained only one or a few genotypes. Identical plants (tussocks) were also found 20-500 m apart and in one case even 1000 m apart. Observed heterozygosity levels (H(O)=0.029) were low, indicating low levels of gene flow, which is in agreement with the selfing nature of other caespitose sedges. Although the number of genotypes in populations is low, these genotypes are genetically very distinct and variation within populations accounted for 55% of the total variation. The absence of a correlation between genetic and geographic distances among populations, and the scattered distribution of genotypes among patches within woodlands, support our hypothesis of rare establishments and subsequent local dispersal within woodlands in this forest floor species, which may benefit from and partly depend on human land use and forest management activities.

  18. Regulation of 5'-adenosine monophosphate deaminase in the freeze tolerant wood frog, Rana sylvatica

    PubMed Central

    Dieni, Christopher A; Storey, Kenneth B

    2008-01-01

    Background The wood frog, Rana sylvatica, is one of a few vertebrate species that have developed natural freeze tolerance, surviving days or weeks with 65–70% of its total body water frozen in extracellular ice masses. Frozen frogs exhibit no vital signs and their organs must endure multiple stresses, particularly long term anoxia and ischemia. Maintenance of cellular energy supply is critical to viability in the frozen state and in skeletal muscle, AMP deaminase (AMPD) plays a key role in stabilizing cellular energetics. The present study investigated AMPD control in wood frog muscle. Results Wood frog AMPD was subject to multiple regulatory controls: binding to subcellular structures, protein phosphorylation, and effects of allosteric effectors, cryoprotectants and temperature. The percentage of bound AMPD activity increased from 20 to 35% with the transition to the frozen state. Bound AMPD showed altered kinetic parameters compared with the free enzyme (S0.5 AMP was reduced, Hill coefficient fell to ~1.0) and the transition to the frozen state led to a 3-fold increase in S0.5 AMP of the bound enzyme. AMPD was a target of protein phosphorylation. Bound AMPD from control frogs proved to be a low phosphate form with a low S0.5 AMP and was phosphorylated in incubations that stimulated PKA, PKC, CaMK, or AMPK. Bound AMPD from frozen frogs was a high phosphate form with a high S0.5 AMP that was reduced under incubation conditions that stimulated protein phosphatases. Frog muscle AMPD was activated by Mg·ATP and Mg·ADP and inhibited by Mg·GTP, KCl, NaCl and NH4Cl. The enzyme product, IMP, uniquely inhibited only the bound (phosphorylated) enzyme from muscle of frozen frogs. Activators and inhibitors differentially affected the free versus bound enzyme. S0.5 AMP of bound AMPD was also differentially affected by high versus low assay temperature (25 vs 5°C) and by the presence/absence of the natural cryoprotectant (250 mM glucose) that accumulates during freezing

  19. A unique Middle Pleistocene beech (Fagus)-rich deciduous broad-leaved forest in the Yangtze Delta Plain, East China: Its climatic and stratigraphic implication

    NASA Astrophysics Data System (ADS)

    Shu, Jun-wu; Wang, Wei-ming

    2012-08-01

    Pollen analysis of Middle Pleistocene sediments from the Yangtze Delta Plain provides a paleoecological reconstruction and has implications for stratigraphic correlation in East China. The pollen assemblage is characterized by high values of Fagus (16.8% on average), which is unusual because Fagus is generally present only sporadically in other lowland Quaternary pollen records from the region. In addition to Fagus, the assemblage has a rich diversity of broad-leaved deciduous trees, including Quercus, Ulmus, Carpinus/Ostrya, Juglans, Betula, and Liquidambar, as well as conifers, including Pinus, Picea, Abies, Larix, and Tsuga. Thus, the pollen flora suggests a broad-leaved deciduous forest mixed with abundant conifers, which developed under cooler and more humid conditions than present. The stable pollen sequence throughout the studied section suggests a stable environment. Beech forests also characterize the Middle Pleistocene of Taiwan and Japan, and thus may be a stratigraphic indicator of the Middle Pleistocene in East Asia. The Yangtze Delta Plain may have been an important refugium for the last survival of Fagus in the lowlands.

  20. A new species of Rhabdias from lungs of the wood frog, Rana sylvatica, in North America: the last sibling of Rhabdias ranae?

    PubMed

    Tkach, Vasyl V; Kuzmin, Yuriy; Pulis, Eric E

    2006-06-01

    Rhabdias bakeri n. sp. is described from specimens found in lungs of the wood frog, Rana sylvatica, from North Dakota. The new species has previously been mistakenly identified as Rhabdias ranae Walton, 1929, a common parasite of the leopard frog, Rana pipiens. The new species differs from R. ranae and Rhabdias joaquinensis Ingles, 1935 by the shape and size of pseudolabia, shape and size of buccal capsule, and wider esophageal bulb. Molecular analysis based on the partial sequences of nuclear 18S rDNA gene, complete sequences of internal transcribed spacer region, and partial sequences of 28S gene demonstrates clear differences between Rhabdias from Ra. sylvatica and Ra. pipiens, and supports the status of R. bakeri as a new species.

  1. Identification and characterization of a novel freezing inducible gene, li16, in the wood frog Rana sylvatica.

    PubMed

    McNally, J Dayre; Wu, Shao-Bo; Sturgeon, Christopher M; Storey, Kenneth B

    2002-06-01

    The wood frog Rana sylvatica survives for weeks during winter hibernation with up to 65% body water frozen as ice. Natural freeze tolerance includes both seasonal and freeze-induced molecular adaptations that control ice formation, deal with long-term ischemia, regulate cell volume changes, and protect macromolecules. This report identifies and characterizes a novel freeze-inducible gene, li16, that codes for a protein of 115 amino acids. Northern blot analysis showed that li16 transcript levels rose quickly during freezing to reach levels 3.7-fold higher than control values after 24 h; immunoblotting showed a parallel 2.4-fold rise in Li16 protein. Regulatory influences on gene expression were assessed. Nuclear runoff assays confirmed that freezing initiated an increase in the rate of li16 transcription, and analysis of signal transduction pathways via in vitro incubation of liver slices implicated a cGMP-mediated pathway in li16 expression. Gene and protein expression in liver was also strongly stimulated by anoxia exposure, whereas the gene was less responsive to dehydration stress. The strong response of li16 to both freezing and anoxia, and the rapid down-regulation of the gene when oxygen was reintroduced, suggest that the Li16 protein may play a role in ischemia resistance during freezing.

  2. Environmental stress responsive expression of the gene li16 in Rana sylvatica, the freeze tolerant wood frog.

    PubMed

    Sullivan, Katrina J; Storey, Kenneth B

    2012-06-01

    Wood frogs (Rana sylvatica) can endure weeks of subzero temperature exposure during the winter with up to 65% of their body water frozen as extracellular ice. Associated with freezing survival is elevated expression of a number of genes/proteins including the unidentified gene, li16, first described in liver. The current study undertakes a broad analysis of li16 expression in response to freezing in 12 tissues of wood frogs as well as expression responses to anoxia and dehydration. Transcript levels of li16 increased significantly after 24h freezing (at -2.5 °C) demonstrating increases of approximately 3-fold in testes, greater than 2-fold in heart, ventral skin and lung, and over 1.5-fold in brain, liver and hind leg muscle as compared to unfrozen controls at 5 °C. Increased li16 transcript levels in brain, muscle and heart were mirrored by elevated Li16 protein in frozen frogs. Significant upregulation of li16 in response to both anoxia and dehydration (both components of freezing) was demonstrated in brain, kidney and heart. Overall, the results indicate that Li16 protein has a significant role to play in cell/organ responses to freezing in wood frogs and that its up-regulation may be linked with oxygen restriction that is a common element in the three stress conditions examined.

  3. Ontogenic delays in effects of nitrite exposure on tiger salamanders (Ambystoma tigrinum tigrinum) and wood frogs (Rana sylvatica).

    PubMed

    Griffis-Kyle, Kerry L

    2005-06-01

    Under certain conditions, nitrite can be present in freshwater systems in quantities that are toxic to the fauna. I exposed wood frog (Rana sylvatica) and eastern tiger salamander (Ambystoma tigrinum tigrinum) embryos and young tadpoles and larvae to elevated concentrations of nitrite in chronic toxicity tests: 0, 0.3, 0.6, 1.2, 2.1, 4.6, and 6.1 mg/L NO2-N, exposing individuals as both embryos and larvae. Nitrite caused significant declines in wood frog hatching success (3.4 mg/L NO2-N, wood frog), and lower concentrations caused significant mortality during the early larval stages (4.6 mg/L NO2-N, salamander; 0.5 mg/L NO2-N, wood frog). Later tests exposing individuals to nitrite only after hatching showed that both wood frog and tiger salamander vulnerability to nitrite declined shortly after hatching. Hence, examining a single life-history stage, especially later in development, may miss critical toxic effects on organisms, causing the researcher potentially to underestimate seriously the ecological consequences of nitrite exposure.

  4. Contents of constituents and antioxidant activity of seed and pulp extracts of Annona coriacea and Annona sylvatica.

    PubMed

    Benites, R S R; Formagio, A S N; Argandoña, E J S; Volobuff, C R F; Trevizan, L N F; Vieira, M C; Silva, M S

    2015-08-01

    The antioxidant potential of fruit pulp and seeds of extracts of the Annona coriacea, and A. sylvatica (Annonaceae) were investigated, as well contents total phenolics, flavonoids, condensed tannins and ascorbic acid. Was used to determine the antioxidant activity the 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH), β-carotene bleaching and ABTS radical cation method. The total phenol, total flavonoid, condensed tannin, and ascorbic acid contents were measured spectrophotometrically. In this study, the pulp and seeds of the fruits were extracted using methanol/water (8:2) for maceration. The seed extracts of A. coriacea demonstrated a moderate antioxidant effect with free radical scavenging activity of 31.53%, by the DPPH test, 51.59% by the β-carotene bleaching test and 159.50 µM trolx/g of extract in the ABTS assay. We found that the hydromethanolic seed extract of A. coriacea had high total phenol (147.08 ± 4.20 mg of GAE/g of extract) and flavonoid (131.18 ± 2.31 mg of QE/g of extract) content. This indicated that the antioxidant activity of the extracts was related to the contents of these constituents.

  5. Metabolic depression induced by urea in organs of the wood frog, Rana sylvatica: effects of season and temperature.

    PubMed

    Muir, Timothy J; Costanzo, Jon P; Lee, Richard E

    2008-03-01

    It has long been suspected that urea accumulation plays a key role in the induction or maintenance of metabolic suppression during extended dormancy in animals from diverse taxa. However, little evidence supporting that hypothesis in living systems exists. We measured aerobic metabolism of isolated organs from the wood frog (Rana sylvatica) in the presence or absence of elevated urea at various temperatures using frogs acclimatized to different seasons. The depressive effect of urea on metabolism was not consistent across organs, seasons, or temperatures. None of the organs from summer frogs, which were tested at 20 degrees C, or from winter frogs tested at 4 degrees C were affected by urea treatment. However, liver, stomach, and heart from spring frogs tested at 4 degrees C had significantly lower metabolic rates when treated with urea as compared with control samples. Additionally, when organs from winter frogs were tested at 10 degrees C, metabolism was significantly decreased in urea-treated liver and stomach by approximately 15% and in urea-treated skeletal muscle by approximately 50%. Our results suggest that the presence of urea depresses the metabolism of living organs, and thereby reduces energy expenditure, but its effect varies with temperature and seasonal acclimatization. The impact of our findings may be wide ranging owing to the number of diverse organisms that accumulate urea during dormancy.

  6. Lenomyrmex hoelldobleri: a new ant species discovered in the stomach of the dendrobatid poison frog, Oophaga sylvatica (Funkhouser).

    PubMed

    Rabeling, Christian; Sosa-Calvo, Jeffrey; O'Connell, Lauren A; Coloma, Luis A; Fernández, Fernando

    2016-01-01

    The ant genus Lenomyrmex was recently discovered and described from mid to high elevation rainforests in southern Central and northwestern South America. Lenomyrmex currently consists of six described species, which are only rarely collected. Here, we add a new species, Lenomyrmex hoelldoblerisp. n., which was discovered in a stomach content sample of the dendrobatid frog, Oophaga sylvatica, from northwestern Ecuador. Lenomyrmex hoelldobleri can be distinguished from other species in the genus by the presence of a well-developed petiolar node, whereas in all other species the node of the petiole is ill-defined. In addition to the shape of the petiolar node, Lenomyrmex hoelldobleri can be distinguished from the morphologically similar Lenomyrmex costatus by (i) the presence of the metanotal suture, (ii) the direction of the striae on dorsum of propodeum (concentrically transverse in Lenomyrmex hoelldobleri, longitudinal in Lenomyrmex costatus), (iii) the finely striate dorsum of postpetiole, (iv) its larger size, and (v) distinctly darker coloration. We also describe the gyne of Lenomyrmex foveolatus. This collection record from northwestern Ecuador extends the geographic distribution of Lenomyrmex foveolatus 400 km south from its previous record in Colombia. A revised taxonomic key to the workers and gynes of all described Lenomyrmex species is provided. We discuss the taxonomic relationship of Lenomyrmex hoelldobleri to other species in the genus and its biology based on the limited information that is currently available. Finally, we briefly discuss the feeding ecology of dendrobatid poison frogs in the context of providing a valuable source of rarely collected and cryptic new ant species.

  7. Anti-apoptotic response during anoxia and recovery in a freeze-tolerant wood frog (Rana sylvatica)

    PubMed Central

    Gerber, Victoria E.M.; Wijenayake, Sanoji

    2016-01-01

    The common wood frog, Rana sylvatica, utilizes freeze tolerance as a means of winter survival. Concealed beneath a layer of leaf litter and blanketed by snow, these frogs withstand subzero temperatures by allowing approximately 65–70% of total body water to freeze. Freezing is generally considered to be an ischemic event in which the blood oxygen supply is impeded and may lead to low levels of ATP production and exposure to oxidative stress. Therefore, it is as important to selectively upregulate cytoprotective mechanisms such as the heat shock protein (HSP) response and expression of antioxidants as it is to shut down majority of ATP consuming processes in the cell. The objective of this study was to investigate another probable cytoprotective mechanism, anti-apoptosis during oxygen deprivation and recovery in the anoxia tolerant wood frog. In particular, relative protein expression levels of two important apoptotic regulator proteins, Bax and p-p53 (S46), and five anti-apoptotic/pro-survival proteins, Bcl-2, p-Bcl-2 (S70), Bcl-xL, x-IAP, and c-IAP in response to normoxic, 24 Hr anoxic exposure, and 4 Hr recovery stages were assessed in the liver and skeletal muscle using western immunoblotting. The results suggest a tissue-specific regulation of the anti-apoptotic pathway in the wood frog, where both liver and skeletal muscle shows an overall decrease in apoptosis and an increase in cell survival. This type of cytoprotective mechanism could be aimed at preserving the existing cellular components during long-term anoxia and oxygen recovery phases in the wood frog. PMID:27042393

  8. Lenomyrmex hoelldobleri: a new ant species discovered in the stomach of the dendrobatid poison frog, Oophaga sylvatica (Funkhouser)

    PubMed Central

    Rabeling, Christian; Sosa-Calvo, Jeffrey; O'Connell, Lauren A.; Coloma, Luis A.; Fernández, Fernando

    2016-01-01

    Abstract The ant genus Lenomyrmex was recently discovered and described from mid to high elevation rainforests in southern Central and northwestern South America. Lenomyrmex currently consists of six described species, which are only rarely collected. Here, we add a new species, Lenomyrmex hoelldobleri sp. n., which was discovered in a stomach content sample of the dendrobatid frog, Oophaga sylvatica, from northwestern Ecuador. Lenomyrmex hoelldobleri can be distinguished from other species in the genus by the presence of a well-developed petiolar node, whereas in all other species the node of the petiole is ill-defined. In addition to the shape of the petiolar node, Lenomyrmex hoelldobleri can be distinguished from the morphologically similar Lenomyrmex costatus by (i) the presence of the metanotal suture, (ii) the direction of the striae on dorsum of propodeum (concentrically transverse in Lenomyrmex hoelldobleri, longitudinal in Lenomyrmex costatus), (iii) the finely striate dorsum of postpetiole, (iv) its larger size, and (v) distinctly darker coloration. We also describe the gyne of Lenomyrmex foveolatus. This collection record from northwestern Ecuador extends the geographic distribution of Lenomyrmex foveolatus 400 km south from its previous record in Colombia. A revised taxonomic key to the workers and gynes of all described Lenomyrmex species is provided. We discuss the taxonomic relationship of Lenomyrmex hoelldobleri to other species in the genus and its biology based on the limited information that is currently available. Finally, we briefly discuss the feeding ecology of dendrobatid poison frogs in the context of providing a valuable source of rarely collected and cryptic new ant species. PMID:27853401

  9. Composition and evaluation of the anti-inflammatory and anticancer activities of the essential oil from Annona sylvatica A. St.-Hil.

    PubMed

    Formagio, Anelise S N; Vieira, Maria do Carmo; Dos Santos, Luiz A C; Cardoso, Claúdia A L; Foglio, Mary Anny; de Carvalho, João Ernesto; Andrade-Silva, Magaiver; Kassuya, Cândida A L

    2013-01-01

    The essential oil from the leaves of Annona sylvatica (EOAS) was extracted by hydrodistillation, and the analysis was performed by gas chromatography-mass spectrometry. The main compounds identified in the EOAS were sesquiterpenes, such as hinesol, z-caryophyllene, β-maaliene, γ-gurjunene, silphiperfol-5-en-3-ol, ledol, cubecol-1-epi, and muurola-3,5-diene. Oral administration of the EOAS (20 and 200 mg/kg) and subcutaneous injection of dexamethasone (0.5 mg/kg, reference drug) significantly inhibited carrageenan- and complete Freund's adjuvant-induced mouse paw edema. The anticancer activity the EOAS showed growth inhibitory activity on all cell lines when administered in a high concentration. The EOAS inhibited the growth of human cancer cell lines with GI(50) values in the range of 36.04-45.37 μg/mL on all of the cell lines tested. This work describes for the first time the anti-inflammatory and anticancer effects of the essential oil of A. sylvatica and its composition. Considering that drugs currently available for the treatment of inflammatory and cancer conditions show undesirable side-effects, the present results may have clinical relevance and open new possibilities for the development of novel anti-inflammatory and anticancer drugs.

  10. Effects of chronic aluminum and copper exposure on growth and development of wood frog (Rana sylvatica) larvae.

    PubMed

    Peles, John D

    2013-09-15

    Wood frogs (Rana sylvatica) were exposed to aluminum (Al; 10, 100, 500, 1000, or 2000 μgL(-1)) or copper (Cu; 1, 10, 50, 100, 200 μgL(-1)) at a pH of 4.70 from the beginning of the larval period through the completion of metamorphosis (range=43-102 days). Observations on mortality, malformation, time to reach specific developmental stages, body mass at these stages, and metamorphic success were made throughout the larval developmental period. Only one case of malformation was observed and mortality was ≤ 10% at all concentrations except the highest Cu concentration where the rate was 33%. All larvae that survived the experiment successfully completed metamorphosis, but significant effects on growth and development occurred for both metals and these were most prominent for Cu. At the highest Al concentration (2000 μgL(-1)), body mass of larvae was significantly lower (reduced by 17% compared to the control) at 20 days post hatching (DPH) and the time to reach the hind-limb (HL), front-limb (FL), and tail resorption (TR) stages was significantly increased (9-10 days longer than the control). Body mass of larvae exposed to the three highest concentrations of Cu (50, 100, 200 μgL(-1)) was reduced by 30-34% at 20 DPH. Exposure to these concentrations also resulted in increased time to reach the HL, FL, and TR stages with larvae in the highest concentration taking 21-29 days longer to reach these stages. Larvae exposed to 10 μgL(-1) Cu also took longer to reach the FL and TR stages of development, and exposure to all Cu concentrations increased tail resorption time by more than two days compared to the control. Although the only observed effects of Al were for a concentration that is probably not ecologically relevant, results demonstrate that environmentally-realistic levels of Cu may have significant biological effects that could influence individual fitness and population-level processes.

  11. Calcium oxalate nephrolithiasis and tubular necrosis in recent metamorphs of Rana sylvatica (Lithobates sylvaticus) fed spinach during the premetamorphic (tadpole) stage.

    PubMed

    Forzán, M J; Ferguson, L V; Smith, T G

    2015-03-01

    Amphibians in the family Ranidae (true frogs) seem highly susceptible to oxalosis, particularly when fed a diet high in oxalic acid during the premetamorphic (tadpole) stage. The authors describe the mortality of 150 captive-raised wood frogs (Rana sylvatica or Lithobates sylvaticus) from oxalate nephrolithiasis and renal tubular necrosis caused by consumption of boiled spinach during tadpole development. Renal lesions were due to intraluminal transparent crystals which were birefringent under polarized light and were identified morphologically and histochemically as composed of calcium oxalate. Evidence of early fibrosis or squamous metaplasia, and a presentation at least 2 weeks after spinach consumption had ended, suggested a subacute course. Tadpole-feeding protocols should avoid plants with high oxalate content (eg, spinach and rhubarb leaves), and any episode of high mortality in captive amphibians along with nephrolithiasis should prompt an evaluation of the feed sources for material with high oxalate content.

  12. Vertical, horizontal and azimuthal variations in leaf photosynthetic characteristics within a Fagus crenata crown in relation to light acclimation.

    PubMed

    Iio, Atsuhiro; Fukasawa, Hisakazu; Nose, Yachiho; Kato, Shuri; Kakubari, Yoshitaka

    2005-05-01

    An understanding of spatial variations in gas exchange parameters in relation to the light environment is crucial for modeling canopy photosynthesis. We measured vertical, horizontal and azimuthal (north and south) variations in photosynthetic capacity (i.e., the maximum rate of carboxylation: Vcmax), nitrogen content (N), leaf mass per area (LMA) and chlorophyll content (Chl) in relation to relative photosynthetic photon flux (rPPF) within a Fagus crenata Blume crown. The horizontal gradient of rPPF was similar in magnitude to the vertical gradient of rPPF from the upper to the lower crown. The rPPF in the north quadrant of the crown was slightly lower than in the south quadrant. Nitrogen content per area (Narea), LMA and Vcmax were strictly proportional to rPPF, irrespective of the vertical direction, horizontal direction and crown azimuth, whereas nitrogen content per dry mass, Chl per area and photosynthetic capacity per dry mass (Vm) were fairly constant. Statistical analyses separating vertical trends from horizontal and azimuthal trends indicated that, although horizontal and vertical light acclimation of leaf properties were similar, there were two significant azimuthal variations: (1) Vcmax was lower in north-facing leaves than in south-facing leaves for a given Narea, indicating low photosynthetic nitrogen-use efficiency (PNUE) of north-facing leaves; and (2) Vcmax was lower in north-facing leaves than in south-facing leaves for a given LMA, indicating low Vm of the north-facing leaves. With respect to the low PNUE of the north-facing leaves, there were no significant azimuthal variations in leaf CO2 conductance from the stomata to the carboxylation site. Biochemical analysis indicated that azimuthal variations in nitrogen allocation to ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and in nitrogen allocation between carboxylation (Rubisco and other Calvin cycle enzymes) and light harvesting machinery (Chl pigment-protein complexes) were not

  13. Modeling of stomatal conductance to estimate stomatal ozone uptake by Fagus crenata, Quercus serrata, Quercus mongolica var. crispula and Betula platyphylla.

    PubMed

    Kinose, Yoshiyuki; Azuchi, Fumika; Uehara, Yui; Kanomata, Tomoaki; Kobayashi, Ayumi; Yamaguchi, Masahiro; Izuta, Takeshi

    2014-11-01

    To construct stomatal conductance models and estimate stomatal O3 uptake for Fagus crenata, Quercus serrata, Quercus mongolica var. crispula and Betula platyphylla, stomatal conductance (gs) was measured in seedlings of the four tree species. Better estimates of gs were made by incorporating the acute effects of O3 on gs into the models and the models could explain 34-52% of the variability in gs. Although the O3 concentration was relatively high in spring from April to May, COU of F. crenata, Q. serrata and Q. mongolica var. crispula were relatively low and the ratios of COU in spring to total COU in one year were 16.8% in all tree species because of low gs limited mainly by leaf pre-maturation and/or low temperature. The COU of B. platyphylla were relatively high mainly because of rapid leaf maturation and lower optimal temperature for stomatal opening.

  14. Photosynthetic responses to ozone of upper and lower canopy leaves of Fagus crenata Blume seedlings grown under different soil nutrient conditions.

    PubMed

    Kinose, Yoshiyuki; Fukamachi, Yoshinobu; Okabe, Shigeaki; Hiroshima, Hiroka; Watanabe, Makoto; Izuta, Takeshi

    2017-04-01

    We aimed to clarify the effects of ozone (O3) on photosynthetic ability of upper and lower canopy leaves of Fagus crenata Blume seedlings grown under different soil nutrient conditions. To accomplish this objective, we analyzed the response of photosynthetic parameters such as maximum carboxylation rate (Vcmax) to cumulative stomatal O3 uptake (ΣFst) and reduction rate of Vcmax per unit ΣFst as an index of detoxification capacity for O3. The seedlings of Fagus crenata were grown for two growing seasons (2014-2015) in nine treatments comprised of a combination of three levels of gas treatments (charcoal-filtered air or 1.0- or 1.5-times ambient O3 concentration) and three levels of soil nutrient treatments (non-fertilized or a supply of relatively low or high concentrations of compound fertilizer). The nutrient supply significantly increased the degree of O3-induced reduction in Vcmax in September. However, nutrient supply did not significantly increase ΣFst and reduce the detoxification capacity for O3. On the other hand, the degree of O3-induced reduction in Vcmax of upper canopy leaves was higher as compared with that of lower canopy leaves in August due to the higher ΣFst. However, the reduction rate of Vcmax per unit ΣFst in lower canopy leaves was higher than that in upper canopy leaves, indicating lower detoxification capacity for O3 in lower canopy leaves. Reduction rate of Vcmax per unit ΣFst over the threshold, which is assumed to be proportional to gross photosynthetic rate, was similar between upper and lower canopy leaves. Therefore, capacity of photosynthetic CO2 assimilation is likely to be associated with detoxification capacity for O3 in upper and lower canopy leaves of F. crenata seedlings grown under different soil nutrient conditions.

  15. Monitoring decay of black gum wood (Nyssa sylvatica) during growth of the shiitake mushroom (Lentinula edodes) using diffuse reflectance infrared spectroscopy.

    PubMed

    Vane, Christopher H

    2003-05-01

    Abstract diffuse reflectance infrared spectroscopy (DRIFT) and elemental analysis were employed to monitor biodegradation of black gum wood (Nyssa sylvatica) during growth of the shiitake mushroom (Lentinula edodes). Black gum was decayed for up to 4.3 years by L. edodes, during which time it was sampled at 19, 31, and 52 months. Biodegraded woods displayed increased % O (w/w) and decreased % C (w/w) relative to the undecayed control. The DRIFT spectra of decayed black gum showed a decrease in relative intensity of absorption bands at 1735 cm(-1) assigned to carboxyl functional groups from xylans and an increase in the absorption band at 1640 cm(-1) assigned to conjugated carbonyl groups originating from lignin. Xylan decay was rapid initially but slowed after 19 months; however, oxidative decay of the lignin side chains occurred throughout the 52-month decay period. Overall elemental and DRIFT data show that both polysaccharides and lignin were decayed during cultivation of the edible white-rot fungus.

  16. Cold acclimation-induced up-regulation of the ribosomal protein L7 gene in the freeze tolerant wood frog, Rana sylvatica.

    PubMed

    Wu, Shaobo; De Croos, J N Amritha; Storey, Kenneth B

    2008-11-15

    Natural freezing survival by the wood frog, Rana sylvatica, involves multiple organ-specific changes in gene expression. The present study used differential display PCR to find cold-responsive genes in wood frog skin. A cDNA was retrieved from skin that was in higher amounts in cold- versus warm-acclimated frogs. The cDNA was used to probe a wood frog liver cDNA library and retrieve a long sequence that, after the further application of 5'RACE, was shown to encode the full sequence of the ribosomal large subunit protein 7 (RPL7) (GenBank accession number AF175983). Wood frog RPL7 contained 246 amino acids and shared 90% identity with Xenopus laevis RPL7, 82-83% with chicken and zebrafish homologues, and 79% with mammalian RPL7. Multiple binding domains found in human RPL7 showed differing degrees of conservation in the frog protein. Transcript levels of rpl7 were elevated up to 4-fold in skin of cold-acclimated frogs as compared with warm-acclimated animals. Organ-specific responses by rpl7 transcripts also occurred when frogs were given survivable freezing exposures. Transcripts rose by 1.8-3.3 fold in brain and skeletal muscle during freezing but were unaffected in central organs such as liver and heart. Up-regulation of rpl7 also occurred in brain of anoxia-exposed frogs and RPL7 protein levels increased strongly in heart under both freezing and dehydration stresses. Cold- and freezing-responsive up-regulation of the rpl7 gene and RPL7 protein in selected organs suggests that targeted changes in selected ribosomal proteins may be an integral part of natural freeze tolerance.

  17. Clinical signs, pathology and dose-dependent survival of adult wood frogs, Rana sylvatica, inoculated orally with frog virus 3 Ranavirus sp., Iridoviridae.

    PubMed

    Forzn, Mara J; Jones, Kathleen M; Vanderstichel, Raphal V; Wood, John; Kibenge, Frederick S B; Kuiken, Thijs; Wirth, Wytamma; Ariel, Ellen; Daoust, Pierre-Yves

    2015-05-01

    Amphibian populations suffer massive mortalities from infection with frog virus 3 FV3, genus Ranavirus, family Iridoviridae, a pathogen also involved in mortalities of fish and reptiles. Experimental oral infection with FV3 in captive-raised adult wood frogs, Rana sylvatica Lithobates sylvaticus, was performed as the first step in establishing a native North American animal model of ranaviral disease to study pathogenesis and host response. Oral dosing was successful LD50 was 10(2.93 2.423.44) p.f.u. for frogs averaging 35mm in length. Onset of clinical signs occurred 614days post-infection p.i. median 11 days p.i. and time to death was 1014 days p.i. median 12 days p.i.. Each tenfold increase in virus dose increased the odds of dying by 23-fold and accelerated onset of clinical signs and death by approximately 15. Ranavirus DNA was demonstrated in skin and liver of all frogs that died or were euthanized because of severe clinical signs. Shedding of virus occurred in faeces 710 days p.i. 34.5days before death and skin sheds 10 days p.i. 01.5days before death of some frogs dead from infection. Most common lesions were dermal erosion and haemorrhages haematopoietic necrosis in bone marrow, kidney, spleen and liver and necrosis in renal glomeruli, tongue, gastrointestinal tract and urinary bladder mucosa. Presence of ranavirus in lesions was confirmed by immunohistochemistry. Intracytoplasmic inclusion bodies probably viral were present in the bone marrow and the epithelia of the oral cavity, gastrointestinal tract, renal tubules and urinary bladder. Our work describes a ranaviruswood frog model and provides estimates that can be incorporated into ranavirus disease ecology models.

  18. Influences of environmental factors on the radial profile of sap flux density in Fagus crenata growing at different elevations in the Naeba Mountains, Japan.

    PubMed

    Kubota, Mitsumasa; Tenhunen, John; Zimmerman, Reiner; Schmidt, Markus; Adiku, Samuel; Kakubari, Yoshitaka

    2005-05-01

    Sap flux density was measured continuously during the 1999 and 2000 growing seasons by the heat dissipation method in natural Fagus crenata Blume (Japanese beech) forests growing between 550 and 1600 m on the northern slope of the Kagura Peak of the Naeba Mountains, Japan. Sap flux density decreased radially toward the inner xylem and the decrease was best expressed in relation to the number of annual rings from the cambium, or in relation to the relative depth between the cambium and the trunk center, rather than as a function of absolute depth. The relative influences of radiation, vapor pressure deficit and soil water on sap flux density during the growing season were similar for the outer and inner xylem, and at all sites. Measurements of soil water content and water potential at a depth of 0.25 m demonstrated that sap flux density responded similarly and sensitively to water potential changes in this soil layer, despite large differences in rooting depth at different elevations, localizing one important control point in the functioning of this forest ecosystem. Identification of the relative influences of radiation, vapor pressure deficit and drying of the upper soil layer on sap flux density provides a framework for in-depth analysis of the control of transpiration in Japanese beech forests. In addition, the finding that the same general controls are operating on sap flux density despite climate gradients and large differences in overall forest stand structure will enhance understanding of water use by forests along elevation gradients.

  19. Biotic and Abiotic Factors Controlling Respiration Rates of Above- and Belowground Woody Debris of Fagus crenata and Quercus crispula in Japan.

    PubMed

    Jomura, Mayuko; Akashi, Yuhei; Itoh, Hiromu; Yuki, Risa; Sakai, Yoshimi; Maruyama, Yutaka

    2015-01-01

    As a large, long-term pool and source of carbon and nutrients, woody litter is an important component of forest ecosystems. The objective of this study was to estimate the effect of the factors that regulate the rate of decomposition of coarse and fine woody debris (CFWD) of dominant tree species in a cool-temperate forest in Japan. Respiration rates of dead stems, branches, and coarse and fine roots of Fagus crenata and Quercus crispula felled 4 years prior obtained in situ ranged from 20.9 to 500.1 mg CO2 [kg dry wood](-1) h(-1) in a one-time measurement in summer. Respiration rate had a significant negative relationship with diameter; in particular, that of a sample of Q. crispula with a diameter of >15 cm and substantial heartwood was low. It also had a significant positive relationship with moisture content. The explanatory variables diameter, [N], wood density, and moisture content were interrelated. The most parsimonious path model showed 14 significant correlations among 8 factors and respiration. Diameter and [C] had large negative direct effects on CFWD respiration rate, and moisture content and species had medium positive direct effects. [N] and temperature did not have direct or indirect effects, and position and wood density had indirect effects. The model revealed some interrelationships between controlling factors. We discussed the influence of the direct effects of explanatory variables and the influence especially of species and position. We speculate that the small R2 value of the most parsimonious model was probably due to the omission of microbial biomass and activity. These direct and indirect effects and interrelationships between explanatory variables could be used to develop a process-based CFWD decomposition model.

  20. Effects of long-term exposure to ammonium sulfate particles on growth and gas exchange rates of Fagus crenata, Castanopsis sieboldii, Larix kaempferi and Cryptomeria japonica seedlings

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Masahiro; Otani, Yoko; Li, Peiran; Nagao, Hiroshi; Lenggoro, I. Wuled; Ishida, Atsushi; Yazaki, Kenichi; Noguchi, Kyotaro; Nakaba, Satoshi; Yamane, Kenichi; Kuroda, Katsushi; Sano, Yuzou; Funada, Ryo; Izuta, Takeshi

    2014-11-01

    To clarify the effects of long-term exposure to ammonium sulfate (AS) particles on growth and physiological functions of forest tree species, seedlings of Fagus crenata, Castanopsis sieboldii, Larix kaempferi and Cryptomeria japonica were exposed to submicron-size AS particles during two growing seasons from 3 June 2011 to 8 October 2012. The mean sulfate concentration in PM2.5 increased during the exposure inside the chamber in 2011 and 2012 by 2.73 and 4.32 μg SO42- m-3, respectively. No significant effects of exposure to AS particles were detected on the whole-plant dry mass of the seedlings. These results indicate that the exposure to submicrometer AS particles at the ambient level for two growing seasons did not significantly affect the growth of the seedlings. No significant effects of exposure to AS particles were found on the net photosynthetic rate in the leaves or needles of F. crenata, C. sieboldii and L. kaempferi seedlings. Also, in the previous-year needles of C. japonica seedlings, exposure to AS particles significantly reduced the net photosynthetic rate, which may be caused by the reduction in the concentration of ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco). On the contrary, in current-year needles of C. japonica seedlings, net photosynthetic rate significantly increased with exposure to AS particles, which may be the result of increases in stomatal conductance and concentrations of Rubisco and chlorophyll. Furthermore, exposure to AS particles correlated with an increase in concentrations of NH4+, free amino acid and total soluble protein, suggesting that AS particles may be deliquesced, absorbed into the leaves and metabolized into amino acid and protein. These results suggest that net photosynthesis in the needles of C. japonica is relatively sensitive to submicron-size AS particles as compared with the other three tree species.

  1. Changes in crown development patterns and current-year shoot structure with light environment and tree height in Fagus crenata (Fagaceae).

    PubMed

    Osada, Noriyuki; Tateno, Ryunosuke; Mori, Akira; Takeda, Hiroshi

    2004-12-01

    The relative effects of light and tree height on the architecture of leader crowns (i.e., the leading section of the main trunk, 100 cm in length) and current-year shoots for a canopy species, Fagus crenata, occupying both the ridge top and the valley bottom in a cool-temperate forest in Japan were investigated. For leader crowns, the number of current-year shoots and leaves increased with increasing tree height, whereas the mean length of current-year shoots increased with increasing relative photon flux density (PFD). The leader crown area decreased, and the depth and leaf area index of leader crowns increased, with increasing relative PFD. The mass of current-year shoots increased with relative PFD. However, this total mass was allocated differently between stems and leaves depending on tree height, such that the relative allocation to stems increased with increasing tree height. Furthermore, stem structures within current-year shoots also changed with height, such that taller trees produced thicker and shorter stems of the same volume. In contrast, leaf structure and leaf biomass allocations changed with relative PFD. Specific leaf area decreased with increasing relative PFD. In addition, leaf number increased more rapidly with increasing individual leaf mass for trees exposed to greater relative PFD. Consequently, the total leaf area supported by a stem of a given diameter decreased with increasing tree height and relative PFD. Thus, the architecture of leader crowns and current-year shoots were related differently to light and tree height, which are considered important for efficient light capture and the growth of small and tall trees in different environments.

  2. Biotic and Abiotic Factors Controlling Respiration Rates of Above- and Belowground Woody Debris of Fagus crenata and Quercus crispula in Japan

    PubMed Central

    Jomura, Mayuko; Akashi, Yuhei; Itoh, Hiromu; Yuki, Risa; Sakai, Yoshimi; Maruyama, Yutaka

    2015-01-01

    As a large, long-term pool and source of carbon and nutrients, woody litter is an important component of forest ecosystems. The objective of this study was to estimate the effect of the factors that regulate the rate of decomposition of coarse and fine woody debris (CFWD) of dominant tree species in a cool-temperate forest in Japan. Respiration rates of dead stems, branches, and coarse and fine roots of Fagus crenata and Quercus crispula felled 4 years prior obtained in situ ranged from 20.9 to 500.1 mg CO2 [kg dry wood]–1 h–1 in a one-time measurement in summer. Respiration rate had a significant negative relationship with diameter; in particular, that of a sample of Q. crispula with a diameter of >15 cm and substantial heartwood was low. It also had a significant positive relationship with moisture content. The explanatory variables diameter, [N], wood density, and moisture content were interrelated. The most parsimonious path model showed 14 significant correlations among 8 factors and respiration. Diameter and [C] had large negative direct effects on CFWD respiration rate, and moisture content and species had medium positive direct effects. [N] and temperature did not have direct or indirect effects, and position and wood density had indirect effects. The model revealed some interrelationships between controlling factors. We discussed the influence of the direct effects of explanatory variables and the influence especially of species and position. We speculate that the small R2 value of the most parsimonious model was probably due to the omission of microbial biomass and activity. These direct and indirect effects and interrelationships between explanatory variables could be used to develop a process-based CFWD decomposition model. PMID:26658727

  3. Osmolyte regulation by TonEBP/NFAT5 during anoxia-recovery and dehydration–rehydration stresses in the freeze-tolerant wood frog (Rana sylvatica)

    PubMed Central

    Al-attar, Rasha; Zhang, Yichi

    2017-01-01

    Background The wood frog, Rana sylvatica, tolerates freezing as a means of winter survival. Freezing is considered to be an ischemic/anoxic event in which oxygen delivery is significantly impaired. In addition, cellular dehydration occurs during freezing because water is lost to extracellular compartments in order to promote freezing. In order to prevent severe cell shrinkage and cell death, it is important for the wood frog to have adaptive mechanisms for osmoregulation. One important mechanism of cellular osmoregulation occurs through the cellular uptake/production of organic osmolytes like sorbitol, betaine, and myo-inositol. Betaine and myo-inositol are transported by the proteins BGT-1 and SMIT, respectively. Sorbitol on the other hand, is synthesized inside the cell by the enzyme aldose reductase. These three proteins are regulated at the transcriptional level by the transcription factor, NFAT5/TonEBP. Therefore, the objective of this study was to elucidate the role of NFAT5/TonEBP in regulating BGT-1, SMIT, and aldose reductase, during dehydration and anoxia in the wood frog muscle, liver, and kidney tissues. Methods Wood frogs were subjected to 24 h anoxia-4 h recovery and 40% dehydration-full rehydration experiments. Protein levels of NFAT5, BGT-1, SMIT, and aldose reductase were studied using immunoblotting in muscle, liver, and kidney tissues. Results Immunoblotting results demonstrated downregulations in NFAT5 protein levels in both liver and kidney tissues during anoxia (decreases by 41% and 44% relative to control for liver and kidney, respectively). Aldose reductase protein levels also decreased in both muscle and kidney tissues during anoxia (by 37% and 30% for muscle and kidney, respectively). On the other hand, BGT-1 levels increased during anoxia in muscle (0.9-fold compared to control) and kidney (1.1-fold). Under 40% dehydration, NFAT5 levels decreased in liver by 53%. Aldose reductase levels also decreased by 42% in dehydrated muscle, and by

  4. Recovery Plan for Phytophthora kernoviae Causing Bleeding Trunk Cankers, Leaf Blight and Stem Dieback in Trees and Shrubs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytophthora kernoviae, a recently described species of Phytophthora, is an invasive pathogen of forest trees and shrubs such as beech (Fagus sylvatica) and rhododendron (Rhododendron ponticum) that has become established in woodlands and public gardens in Cornwall, United Kingdom. Although the ori...

  5. ESTIMATING ROOT RESPIRATION IN SPRUCE AND BEECH: DECREASES IN SOIL RESPIRATION FOLLOWING GIRDLING

    EPA Science Inventory

    A study was undertaken to follow seasonal fluxes of CO2 from soil and to estimate the contribution of autotrophic (root + mycorrhizal) to total soil respiration (SR) in a mixed stand of European beech (Fagus sylvatica) and Norway spruce (Picea abies) near Freising, Germany. Matu...

  6. SOIL CO2 EFFLUX FROM ISOTOPICALLY LABELED BEECH AND SPRUCE IN SOUTHERN GERMANY

    EPA Science Inventory

    • Carbon acquisition and transport to roots in forest trees is difficult to quantify and is affected by a number of factors, including micrometeorology and anthropogenic stresses. The canopies of mature European beech (Fagus sylvatica) and Norway spruce (Picea abies) were expose...

  7. DECLINE IN SOIL CO2 EFFLUX FOLLOWING TREE GIRTLING IN MATURE BEECH AND SPRUCE STANDS IN GERMANY

    EPA Science Inventory

    Studies were undertaken to estimate the contribution of autotrophic respiration to total soil CO2 efflux in stands of mature European beech (Fagus sylvatica) and Norway spruce (Picea abies) near Freising, Germany. Five mature trees of each species were girdled to eliminate carbo...

  8. Carbon flux to woody tissues in a beech/spruce forest during summer and in response to chronic O3 exposure

    EPA Science Inventory

    The present study compares the dynamics in carbon (C) allocation of adult deciduous beech (Fagus sylvatica) and evergreen spruce (Picea abies) during summer and in response to seven-year-long exposure with twice-ambient ozone (O3) concentrations (2 × O3). Focus was on the respira...

  9. The first host records for the Nearctic species Triraphis discoideus (Hymenoptera: Braconidae: Rogadinae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Limacodid larvae were collected from 2004 – 2007 on leaves of the following host plants in the District of Columbia and Maryland: Carya glabra, pignut hickory; Quercus alba, white oak; Quercus rubra, northern red oak; Nyssa sylvatica, black gum; Prunus serotina, black cherry; and Fagus grandifolia, ...

  10. Understory Density Characteristics in Several Midlatitude Temperature Forests

    DTIC Science & Technology

    2003-03-01

    Vaccinium corymbosum ), black gum (Nyssa sylvatica), white oak (Q. alba), mockemut hickory (Carya tomentosa), American beech (Fagus grandifolia), and...Cedar Juniperis virginiana Red Juniper U Fraser Magnolia Magnolia fraseri Umbrella-tree U Highbush Blueberry Vaccinium corymbosum Unkn. U Loblolly Pine...plants and shrubs include ferns (many species), lowbush blueberry ( Vaccinium augustifolium), southern running-pine (Lycopodium digitatum), poison ivy

  11. Counting scars on tree stems to assess rockfall hazards: A low effort approach, but how reliable?

    NASA Astrophysics Data System (ADS)

    Trappmann, Daniel; Stoffel, Markus

    2013-01-01

    Rockfall is a widespread and hazardous process in mountain environments, but data on past events are only rarely available. Growth-ring series from trees impacted by rockfall were successfully used in the past to overcome the lack of archival records. Dendrogeomorphic techniques have been demonstrated to allow very accurate dating and reconstruction of spatial and temporal rockfall activity, but the approach has been cited to be labor intensive and time consuming. In this study, we present a simplified method to quantify rockfall processes on forested slopes requiring less time and efforts. The approach is based on a counting of visible scars on the stem surface of Common beech (Fagus sylvatica L.). Data are presented from a site in the Inn valley (Austria), where rocks are frequently detached from an ~ 200-m-high, south-facing limestone cliff. We compare results obtained from (i) the "classical" analysis of growth disturbances in the tree-ring series of 33 Norway spruces (Picea abies (L.) Karst.) and (ii) data obtained with a scar count on the stem surface of 50 F. sylvatica trees. A total of 277 rockfall events since A.D. 1819 could be reconstructed from tree-ring records of P. abies, whereas 1140 scars were observed on the stem surface of F. sylvatica. Absolute numbers of rockfalls (and hence return intervals) vary significantly between the approaches, and the mean number of rockfalls observed on the stem surface of F. sylvatica exceeds that of P. abies by a factor of 2.7. On the other hand, both methods yield comparable data on the spatial distribution of relative rockfall activity. Differences may be explained by a great portion of masked scars in P. abies and the conservation of signs of impacts on the stem of F. sylvatica. Besides, data indicate that several scars on the bark of F. sylvatica may stem from the same impact and thus lead to an overestimation of rockfall activity.

  12. On the functional role of tree species in two forest ecosystems

    NASA Astrophysics Data System (ADS)

    Kutsch, Werner Leo; Herbst, Mathias; Liu, Chunjiang

    2010-05-01

    Ecosystems can be characterized in different ways depending on the point of view or the scientific background. Summarizing these views, one can describe ecosystems by their structure and metabolism. The species composition is part of the ecosystem structure. Moreover, ecosystem structures are detailed by biomass or soil and canopy architecture. Ecosystem metabolism represents the functional side. It can be described by primary production, nutrient retention, or control and use of water resources. Structure and function are connected. The biomass that is produced by the ecosystem metabolism is used to construct the ecosystem structure, which vice versa the structure controls the efficiency of the ecosystem metabolism. One hypothesis is that ecosystems with many species provide a more efficient metabolism than ecosystems with fewer species. We tested this hypothesis by using two ecosystems functional parameters in several deciduous forest ecosystems. The first example are possible relations between canopy carbon uptake capacity (FP,max) as measured with the eddy covariance technique (ecosystem metabolism) and LAI as well as spatial and temporal variability of leaf traits (ecosystem structure). We investigated leaf traits of four tree species in a mixed deciduous forest in northern Germany in search for an explanation for the differences in canopy photosynthetic capacity between different forest sectors consisting of different species and species numbers (Quercus robur + Fagus sylvatica, Fraxinus excelsior + Alnus glutinosa, pure Fagus sylvatica). We identified leaf traits that were adjusted to the canopy light profile in species-specific ways, and for these traits the plasticity indices were calculated. Canopy photosynthetic capacity did neither correlate with leaf area index (LAI) alone nor with canopy plasticity indices which were almost similar between the three sectors although it differed at the species level. It is suggested that the spatial variability of FP

  13. Leaf Uptake of Nitrogen Dioxide (NO2) Under Different Environmental Conditions.

    NASA Astrophysics Data System (ADS)

    Chaparro-Suarez, I.; Thielmann, A.; Meixner, F. X.; Kesselmeier, J.

    2005-12-01

    The chemical budget of Ozone in the troposphere is largely determined by the concentration of NOx (NO, NO2) within a photostationary equilibrium. It is well known that atmospheric concentration is strongly influenced by the bi-directional exchange of NO2. However, there is some debate about the magnitude of the compensation point. Therefore, we investigated the uptake of atmospheric NO2 by trees in relation to atmospheric NO2 concentrations. Using the dynamic chamber technique and a sensitive and specific NO-analysator (CLD 780, Eco Physics) we measured the uptake of NO2 by four different tree species (Betula pendula, Fagus sylvatica, Quercus ilex und Pinus sylvestris) under field and laboratory conditions. Simultaneous measurements of CO2 exchange and transpiration were performed to track photosynthesis and stomatal conductance. Depending on tree species we found the exchange to be controlled by very low NO2 compensation points sometimes reaching zero values (no emission) under laboratory conditions. In the field a high compensation point for European beech (Fagus sylvatica) was observed, which is understood as a result of complex atmospheric conditions.

  14. Holocene vegetation and fire history of the mountains of northern Sicily (Italy)

    USGS Publications Warehouse

    Tinner, Willy; Vescovi, Elisa; Van Leeuwen, Jacqueline; Colombaroli, Daniele; Henne, Paul; Kaltenrieder, Petra; Morales-Molino, Cesar; Beffa, Giorgia; Gnaegi, Bettina; Van der Knaap, Pim W O; La Mantia, Tommaso; Pasta, Salvatore

    2016-01-01

    Knowledge about vegetation and fire history of the mountains of Northern Sicily is scanty. We analysed five sites to fill this gap and used terrestrial plant macrofossils to establish robust radiocarbon chronologies. Palynological records from Gorgo Tondo, Gorgo Lungo, Marcato Cixé, Urgo Pietra Giordano and Gorgo Pollicino show that under natural or near natural conditions, deciduous forests (Quercus pubescens, Q. cerris, Fraxinus ornus, Ulmus), that included a substantial portion of evergreen broadleaved species (Q. suber, Q. ilex, Hedera helix), prevailed in the upper meso-mediterranean belt. Mesophilous deciduous and evergreen broadleaved trees (Fagus sylvatica, Ilex aquifolium) dominated in the natural or quasi-natural forests of the oro-mediterranean belt. Forests were repeatedly opened for agricultural purposes. Fire activity was closely associated with farming, providing evidence that burning was a primary land use tool since Neolithic times. Land use and fire activity intensified during the Early Neolithic at 5000 bc, at the onset of the Bronze Age at 2500 bc and at the onset of the Iron Age at 800 bc. Our data and previous studies suggest that the large majority of open land communities in Sicily, from the coastal lowlands to the mountain areas below the thorny-cushion Astragalus belt (ca. 1,800 m a.s.l.), would rapidly develop into forests if land use ceased. Mesophilous Fagus-Ilex forests developed under warm mid Holocene conditions and were resilient to the combined impacts of humans and climate. The past ecology suggests a resilience of these summer-drought adapted communities to climate warming of about 2 °C. Hence, they may be particularly suited to provide heat and drought-adaptedFagus sylvatica ecotypes for maintaining drought-sensitive Central European beech forests under global warming conditions.

  15. Elevated CO2 enrichment induces a differential biomass response in a mixed species temperate forest plantation.

    PubMed

    Smith, Andrew R; Lukac, Martin; Hood, Robin; Healey, John R; Miglietta, Franco; Godbold, Douglas L

    2013-04-01

    In a free-air carbon dioxide (CO(2)) enrichment study (BangorFACE), Alnus glutinosa, Betula pendula and Fagus sylvatica were planted in areas of one-, two- and three-species mixtures (n = 4). The trees were exposed to ambient or elevated CO(2) (580 μmol mol(-1)) for 4 yr, and aboveground growth characteristics were measured. In monoculture, the mean effect of CO(2) enrichment on aboveground woody biomass was + 29, + 22 and + 16% for A. glutinosa, F. sylvatica and B. pendula, respectively. When the same species were grown in polyculture, the response to CO(2) switched to + 10, + 7 and 0% for A. glutinosa, B. pendula and F. sylvatica, respectively. In ambient atmosphere, our species grown in polyculture increased aboveground woody biomass from 12.9 ± 1.4 to 18.9 ± 1.0 kg m(-2), whereas, in an elevated CO(2) atmosphere, aboveground woody biomass increased from 15.2 ± 0.6 to 20.2 ± 0.6 kg m(-2). The overyielding effect of polyculture was smaller (+ 7%) in elevated CO(2) than in an ambient atmosphere (+ 18%). Our results show that the aboveground response to elevated CO(2) is affected significantly by intra- and interspecific competition, and that the elevated CO(2) response may be reduced in forest communities comprising tree species with contrasting functional traits.

  16. Loss of epiphytic diversity along a latitudinal gradient in southern Europe.

    PubMed

    Aragón, Gregorio; Martínez, Isabel; García, Aroa

    2012-06-01

    Latitudinal gradients that involve macroclimatic changes can affect the diversity of several groups of plants and animals. Here we examined the effect of a latitudinal gradient on epiphytic communities on a single host species (Fagus sylvatica) to test the core-periphery theory. The latitudinal span considered, covering two biogeographic regions, is associated with major changes in rainfall during the dry season. Because bryophytes and lichens are poikilohydric, we hypothesized that their species richness and composition might vary at different latitudes. We also speculated how epiphytic communities may respond to future climate change. The present study was carried out in Spain, and three latitudes that cover the distributional range of F. sylvatica were selected. The presence/absence and coverage of epiphytic lichens and bryophytes were identified on 540 trees (180 in each zone). We found consistent south to north change in the total richness and in the richness of bryophytes and of lichens separately, all of which tend to increase at higher latitudes due to the presence of several hygrophytic species. Epiphytic composition also differed significantly among the three latitudes, and the similarity decreased when the latitudinal span was greater. In addition, high species turnover was driven by the increased rainfall at higher latitudes. We conclude that epiphytic communities have a similar pattern to the predictors of the core-periphery theory from populations, and they suffer a great impoverishment in species richness at lower latitudes, coincident with the southern boundary of the F. sylvatica distribution.

  17. Reading the Leaves' Palm: Leaf Traits and Herbivory along the Microclimatic Gradient of Forest Layers.

    PubMed

    Stiegel, Stephanie; Entling, Martin H; Mantilla-Contreras, Jasmin

    2017-01-01

    Microclimate in different positions on a host plant has strong direct effects on herbivores. But little is known about indirect effects due to changes of leaf traits. We hypothesized that herbivory increases from upper canopy to lower canopy and understory due to a combination of direct and indirect pathways. Furthermore, we hypothesized that herbivory in the understory differs between tree species in accordance with their leaf traits. We investigated herbivory by leaf chewing insects along the vertical gradient of mixed deciduous forest stands on the broad-leaved tree species Fagus sylvatica L. (European beech) with study sites located along a 140 km long transect. Additionally, we studied juvenile Acer pseudoplatanus L. (sycamore maple) and Carpinus betulus L. (hornbeam) individuals within the understory as a reference of leaf traits in the same microclimate. Lowest levels of herbivory were observed in upper canopies, where temperatures were highest. Temperature was the best predictor for insect herbivory across forest layers in our study. However, the direction was opposite to the generally known positive relationship. Herbivory also varied between the three tree species with lowest levels for F. sylvatica. Leaf carbon content was highest for F. sylvatica and probably indicates higher amounts of phenolic defense compounds. We conclude that the effect of temperature must have been indirect, whereby the expected higher herbivory was suppressed due to unfavorable leaf traits (lower nitrogen content, higher toughness and carbon content) of upper canopy leaves compared to the understory.

  18. Reading the Leaves’ Palm: Leaf Traits and Herbivory along the Microclimatic Gradient of Forest Layers

    PubMed Central

    Entling, Martin H.; Mantilla-Contreras, Jasmin

    2017-01-01

    Microclimate in different positions on a host plant has strong direct effects on herbivores. But little is known about indirect effects due to changes of leaf traits. We hypothesized that herbivory increases from upper canopy to lower canopy and understory due to a combination of direct and indirect pathways. Furthermore, we hypothesized that herbivory in the understory differs between tree species in accordance with their leaf traits. We investigated herbivory by leaf chewing insects along the vertical gradient of mixed deciduous forest stands on the broad-leaved tree species Fagus sylvatica L. (European beech) with study sites located along a 140 km long transect. Additionally, we studied juvenile Acer pseudoplatanus L. (sycamore maple) and Carpinus betulus L. (hornbeam) individuals within the understory as a reference of leaf traits in the same microclimate. Lowest levels of herbivory were observed in upper canopies, where temperatures were highest. Temperature was the best predictor for insect herbivory across forest layers in our study. However, the direction was opposite to the generally known positive relationship. Herbivory also varied between the three tree species with lowest levels for F. sylvatica. Leaf carbon content was highest for F. sylvatica and probably indicates higher amounts of phenolic defense compounds. We conclude that the effect of temperature must have been indirect, whereby the expected higher herbivory was suppressed due to unfavorable leaf traits (lower nitrogen content, higher toughness and carbon content) of upper canopy leaves compared to the understory. PMID:28099483

  19. Effects of drought on monocultures and mixtures of British deciduous tree species

    NASA Astrophysics Data System (ADS)

    Göransson, Hans; Bambrick, Michael; Godbold, Douglas

    2013-04-01

    In plots of six year old stands of Alnus glutinosa, Betula pendula, Fagus sylvatica and a mixture of the three species, subcanopy roofs were constructed. The roofs covered 70% of the total area and were made of transparent plastic. Using the roofs rain water was excluded from the plots from June to beginning of November 2010 and mid April to mid September 2011. Leaf biomass was negatively affected by the drought. Alnus decreased most in above ground biomass whereas Fagus was unaffected by the drought. Fine root production, as measured by ingrowth nets, was lower in the drought treatment than in the controls for all species. This was reflected in the standing fine root biomass, which was after 2 years lower in the top 10 cm in the drought than in the control. Soil respiration decreased during drought. Alnus had the highest soil respiration and Fagus the lowest in both the treatment and control stands during the time the roofs were on, but differences between species did not persist during the winter. No significant flush of CO2 due to a rewetting effect could be detected. The measured cumulative soil CO2 efflux after the experiment was significantly lower in the drought than in the control except for the birch plots. Our results indicate that there is no large rewetting effect compensating for the lower respiration during the growth season due to drought and differences between species in carbon turnover during the growth season disappears after the growth season.

  20. The importance of biotic factors in predicting global change effects on decomposition of temperate forest leaf litter.

    PubMed

    Rouifed, Soraya; Handa, I Tanya; David, Jean-François; Hättenschwiler, Stephan

    2010-05-01

    Increasing atmospheric CO(2) and temperature are predicted to alter litter decomposition via changes in litter chemistry and environmental conditions. The extent to which these predictions are influenced by biotic factors such as litter species composition or decomposer activity, and in particular how these different factors interact, is not well understood. In a 5-week laboratory experiment we compared the decomposition of leaf litter from four temperate tree species (Fagus sylvatica, Quercus petraea, Carpinus betulus and Tilia platyphyllos) in response to four interacting factors: elevated CO(2)-induced changes in litter quality, a 3 degrees C warmer environment during decomposition, changes in litter species composition, and presence/absence of a litter-feeding millipede (Glomeris marginata). Elevated CO(2) and temperature had much weaker effects on decomposition than litter species composition and the presence of Glomeris. Mass loss of elevated CO(2)-grown leaf litter was reduced in Fagus and increased in Fagus/Tilia mixtures, but was not affected in any other leaf litter treatment. Warming increased litter mass loss in Carpinus and Tilia, but not in the other two litter species and in none of the mixtures. The CO(2)- and temperature-related differences in decomposition disappeared completely when Glomeris was present. Overall, fauna activity stimulated litter mass loss, but to different degrees depending on litter species composition, with a particularly strong effect on Fagus/Tilia mixtures (+58%). Higher fauna-driven mass loss was not followed by higher C mineralization over the relatively short experimental period. Apart from a strong interaction between litter species composition and fauna, the tested factors had little or no interactive effects on decomposition. We conclude that if global change were to result in substantial shifts in plant community composition and macrofauna abundance in forest ecosystems, these interacting biotic factors could have

  1. Observations on the Stomatal Control of NO2 Exchange.

    NASA Astrophysics Data System (ADS)

    Kesselmeier, J.; Chaparro-Suarez, I. G.; Meixner, F. X.

    2005-12-01

    Nitrogen oxides play a central role in tropospheric chemistry especially in the formation of tropospheric ozone, acid rain and hydroxyl radical as well as in CH4 and CO oxidation processes. NO2 can be assimilated and emitted by the plant leaves as well. We investigated the impact of the stomatal regulation with four tree species (Betula pendula, Fagus sylvatica, Quercus ilex und Pinus sylvestris) by exposure of leaves to the hormone abscisic acid inducing stomatal closure. The results showed that the NO2 uptake was strongly dependent on stomatal aperture. The uptake correlated linearly with stomatal (leaf) conductance in case of all four tree species investigated. In contrast an NO2 emission was observed with beech in the dark when stomata were basically closed.

  2. Nothocasis rosariae sp. n., a new sylvicolous, montane species from southern Europe (Lepidoptera: Geometridae, Larentiinae).

    PubMed

    Scalercio, Stefano; Infusino, Marco; Hausmann, Axel

    2016-09-05

    In this paper, we describe Nothocasis rosariae sp. n. as the second European species belonging to the genus Nothocasis Prout, 1937. Differential features from its allopatric sibling species N. sertata (Hübner, 1817) are presented basing on wing pattern, morphology of male and female genitalia, and molecular data (COI barcode region). The type series is designated from southern Italy, but one examined specimen was collected in Epirus, Greece. The largest phenotypic and genetic variation was observed in the Pollino Massif, northern Calabria, whilst the population of the locus typicus in the Sila Massif, central Calabria, appears to be more homogeneous. 128 individuals were collected in mountainous beech forests from late August to mid-November. We hypothesize that larvae of N. rosariae sp. n. feed on Fagus sylvatica whilst those of its sibling species, N. sertata, feed on Acer.

  3. Phytophthora kernoviae sp. nov., an invasive pathogen causing bleeding stem lesions on forest trees and foliar necrosis of ornamentals in the UK.

    PubMed

    Brasier, Clive M; Beales, Paul A; Kirk, Susan A; Denman, Sandra; Rose, Joan

    2005-08-01

    A new Phytophthora pathogen of trees and shrubs, previously informally designated Phytophthora taxon C, is formally named here as P. kernoviae. P. kernoviae was discovered in late 2003 during surveys of woodlands in Cornwall, south-west England, for the presence of another invasive pathogen, P. ramorum. P. kernoviae is self-fertile (homothallic), having plerotic oogonia, often with distinctly tapered stalks and amphigynous antheridia. It produces papillate sporangia, sometimes markedly asymmetric with medium length pedicels. Its optimum temperature for growth is ca 18 degrees C and upper limit ca 26 degrees. Currently, P. kernoviae is especially noted for causing bleeding stem lesions on mature Fagus sylvatica and foliar and stem necrosis of Rhododendron ponticum. P. kernoviae is the latest of several invasive tree Phytophthoras recently identified in the UK. Its geographical origins and the possible plant health risk it poses are discussed.

  4. Elevated aluminium concentration in acidified headwater streams lowers aquatic hyphomycete diversity and impairs leaf-litter breakdown.

    PubMed

    Baudoin, J M; Guérold, F; Felten, V; Chauvet, E; Wagner, P; Rousselle, P

    2008-08-01

    Aquatic hyphomycetes play an essential role in the decomposition of allochthonous organic matter which is a fundamental process driving the functioning of forested headwater streams. We studied the effect of anthropogenic acidification on aquatic hyphomycetes associated with decaying leaves of Fagus sylvatica in six forested headwater streams (pH range, 4.3-7.1). Non-metric multidimensional scaling revealed marked differences in aquatic hyphomycete assemblages between acidified and reference streams. We found strong relationships between aquatic hyphomycete richness and mean Al concentration (r = -0.998, p < 0.0001) and mean pH (r = 0.962, p < 0.002), meaning that fungal diversity was severely depleted in acidified streams. By contrast, mean fungal biomass was not related to acidity. Leaf breakdown rate was drastically reduced under acidic conditions raising the issue of whether the functioning of headwater ecosystems could be impaired by a loss of aquatic hyphomycete species.

  5. Isolation of functional RNA from plant tissues rich in phenolic compounds.

    PubMed

    Schneiderbauer, A; Sandermann, H; Ernst, D

    1991-08-15

    A method for the isolation of RNA from different tissues of trees (seedlings, saplings, and adult trees) is described. Using this procedure it is possible to remove large amounts of disturbing polyphenolic compounds from nucleic acids. The method involves an acetone treatment of the freeze-dried and powdered plant material, the use of high salt concentrations in the extraction buffer and an aqueous two-phase system. These steps were combined with the conventional phenol/chloroform extraction and CsCl centrifugation. The method has been successfully applied to the isolation and purification of RNA from pine (Pinus sylvestris L. and Pinus mugo Turr.), Norway spruce (Picea abies L.), and beech (Fagus sylvatica L.). The functional quality of RNA extracted by this procedure has been characterized by its uv spectrum, by agarose gel electrophoresis with ethidium bromide staining, Northern blot hybridization, and in vitro translation.

  6. Future impacts of nitrogen deposition and climate change scenarios on forest crown defoliation.

    PubMed

    De Marco, Alessandra; Proietti, Chiara; Cionni, Irene; Fischer, Richard; Screpanti, Augusto; Vitale, Marcello

    2014-11-01

    Defoliation is an indicator for forest health in response to several stressors including air pollutants, and one of the most important parameters monitored in the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests). The study aims to estimate crown defoliation in 2030, under three climate and one nitrogen deposition scenarios, based on evaluation of the most important factors (meteorological, nitrogen deposition and chemical soil parameters) affecting defoliation of twelve European tree species. The combination of favourable climate and nitrogen fertilization in the more adaptive species induces a generalized decrease of defoliation. On the other hand, severe climate change and drought are main causes of increase in defoliation in Quercus ilex and Fagus sylvatica, especially in Mediterranean area. Our results provide information on regional distribution of future defoliation, an important knowledge for identifying policies to counteract negative impacts of climate change and air pollution.

  7. Karyotypes, B-chromosomes and meiotic abnormalities in 13 populations of Alebra albostriella and A. wahlbergi (Hemiptera, Auchenorrhyncha, Cicadellidae) from Greece.

    PubMed

    Kuznetsova, Valentina G; Golub, Natalia V; Aguin-Pombo, Dora

    2013-11-26

    In this work 13 populations of the leafhopper species Alebra albostriella (Fallén, 1826) (6 populations) and A. wahlbergi (Boheman, 1845) (7 populations) (Cicadellidae: Typhlocybinae) from Greece were studied cytogenetically. We examined chromosomal complements and meiosis in 41 males of A. albostriella sampled from Castanea sativa, Fagus sylvatica and Quercus cerris and in 21 males of A. wahlbergi sampled from C. sativa, Acer opalus and Ulmus sp. The species were shown to share 2n = 22 + X(0) and male meiosis of the chiasmate preductional type typical for Auchenorrhyncha. In all populations of A. albostriella and in all but two populations of A. wahlbergi B chromosomes and/or different meiotic abnormalities including the end-to-end non-homologous chromosomal associations, translocation chains, univalents, anaphasic laggards besides aberrant sperms were encountered. This study represents the first chromosomal record for the genus Alebra and one of the few population-cytogenetic studies in the Auchenorrhyncha.

  8. Mechanical behaviour analyses of sap ascent in vascular plants.

    PubMed

    Perez-Diaz, Jose-Luis; Garcia-Prada, Juan-Carlos; Romera-Juarez, Fernando; Diez-Jimenez, Efren

    2010-09-01

    A pure mechanical anisotropic model of a tree trunk has been developed based on the 3D finite element method. It simulates the microscopic structure of vessels in the trunk of a European beech (Fagus sylvatica) in order to study and analyse its mechanical behaviour with different configurations of pressures in the conduits of xylem and phloem. The dependence of the strains at the inner bark was studied when sap pressure changed. The comparison with previously published experimental data leads to the conclusion that a great tensile stress-or 'negative pressure'-must exist in the water column in order to achieve the measured strains if only the mechanical point of view is taken into account. Moreover, the model can help to design experiments where qualitatively knowing the strains and the purely mechanical behaviour of the tree is required.

  9. Mechanical behaviour analyses of sap ascent in vascular plants

    PubMed Central

    Perez-Diaz, Jose-Luis; Garcia-Prada, Juan-Carlos; Romera-Juarez, Fernando

    2010-01-01

    A pure mechanical anisotropic model of a tree trunk has been developed based on the 3D finite element method. It simulates the microscopic structure of vessels in the trunk of a European beech (Fagus sylvatica) in order to study and analyse its mechanical behaviour with different configurations of pressures in the conduits of xylem and phloem. The dependence of the strains at the inner bark was studied when sap pressure changed. The comparison with previously published experimental data leads to the conclusion that a great tensile stress—or ‘negative pressure’—must exist in the water column in order to achieve the measured strains if only the mechanical point of view is taken into account. Moreover, the model can help to design experiments where qualitatively knowing the strains and the purely mechanical behaviour of the tree is required. PMID:21886343

  10. Site-adapted admixed tree species reduce drought susceptibility of mature European beech.

    PubMed

    Metz, Jérôme; Annighöfer, Peter; Schall, Peter; Zimmermann, Jorma; Kahl, Tiemo; Schulze, Ernst-Detlef; Ammer, Christian

    2016-02-01

    Some forest-related studies on possible effects of climate change conclude that growth potential of European beech (Fagus sylvatica L.) might be impaired by the predicted increase in future serious drought events during the growing season. Other recent research suggests that not only multiyear increment rates but also growth resistance and recovery of beech during, respectively, after dry years may differ between pure and mixed stands. Thus, we combined dendrochronological investigations and wood stable isotope measurements to further investigate the impact of neighborhood diversity on long-term performance, short-term drought response and soil water availability of European beech in three major geographic regions of Germany. During the last four decades, target trees whose competitive neighborhood consisted of co-occurring species exhibited a superior growth performance compared to beeches in pure stands of the same investigation area. This general pattern was also found in exceptional dry years. Although the summer droughts of 1976 and 2003 predominantly caused stronger relative growth declines if target trees were exposed to interspecific competition, with few exceptions they still formed wider annual rings than beeches growing in close-by monocultures. Within the same study region, recovery of standardized beech target tree radial growth was consistently slower in monospecific stands than in the neighborhood of other competitor species. These findings suggest an improved water availability of beech in mixtures what is in line with the results of the stable isotope analysis. Apparently, the magnitude of competitive complementarity determines the growth response of target beech trees in mixtures. Our investigation strongly suggest that the sensitivity of European beech to environmental constrains depends on neighborhood identity. Therefore, the systematic formation of mixed stands tends to be an appropriate silvicultural measure to mitigate the effects of global

  11. The influence of masting phenomenon on growth-climate relationships in trees: explaining the influence of previous summers' climate on ring width.

    PubMed

    Hacket-Pain, Andrew J; Friend, Andrew D; Lageard, Jonathan G A; Thomas, Peter A

    2015-03-01

    Tree growth is frequently linked to weather conditions prior to the growing season but our understanding of these lagged climate signatures is still poorly developed. We investigated the influence of masting behaviour on the relationship between growth and climate in European Beech (Fagus sylvatica L.) using a rare long-term dataset of seed production and a new regional tree ring chronology. Fagus sylvatica is a masting species with synchronous variations in seed production which are strongly linked to the temperature in the previous two summers. We noted that the weather conditions associated with years of heavy seed production (mast years) were the same as commonly reported correlations between growth and climate for this species. We tested the hypothesis that a trade-off between growth and reproduction in mast years could be responsible for the observed lagged correlations between growth and previous summers' temperatures. We developed statistical models of growth based on monthly climate variables, and show that summer drought (negative correlation), temperature of the previous summer (negative) and temperature of the summer 2 years previous (positive) are significant predictors of growth. Replacing previous summers' temperature in the model with annual seed production resulted in a model with the same predictive power, explaining the same variance in growth. Masting is a common behaviour in many tree species and these findings therefore have important implications for the interpretation of general climate-growth relationships. Lagged correlations can be the result of processes occurring in the year of growth (that are determined by conditions in previous years), obviating or reducing the need for 'carry-over' processes such as carbohydrate depletion to be invoked to explain this climate signature in tree rings. Masting occurs in many tree species and these findings therefore have important implications for the interpretation of general climate

  12. Effects of road de-icing salt (NaCl) on larval wood frogs (Rana sylvatica).

    PubMed

    Sanzo, Domenico; Hecnar, Stephen J

    2006-03-01

    Vast networks of roads cover the earth and have numerous environmental effects including pollution. A major component of road runoff in northern countries is salt (mostly NaCl) used as a winter de-icing agent, but few studies of effects of road salts on aquatic organisms exist. Amphibians require aquatic habitats and chemical pollution is implicated as a major factor in global population declines. We exposed wood frog tadpoles to NaCl. Tests revealed 96-h LC50 values of 2,636 and 5,109 mg/l and tadpoles experienced reduced activity, weight, and displayed physical abnormalities. A 90 d chronic experiment revealed significantly lower survivorship, decreased time to metamorphosis, reduced weight and activity, and increased physical abnormalities with increasing salt concentration (0.00, 0.39, 77.50, 1,030.00 mg/l). Road salts had toxic effects on larvae at environmentally realistic concentrations with potentially far-ranging ecological impacts. More studies on the effects of road salts are warranted.

  13. BIOCONCENTRATION AND METABOLISM OF ALL-TRANS RETINOIC ACID BY RANA SYLVATICA AND RANA CLAMITANS TADPOLES

    EPA Science Inventory

    Retinoids, which are Vitamin A derivatives, are important signaling molecules that regulate processes critical for development in all vertebrates. The objective of our study was to examine uptake and metabolism of all-trans retinoic acid...

  14. Energy potential of waste from 10 forest species in the North of Spain (Cantabria).

    PubMed

    Pérez, S; Renedo, C J; Ortiz, A; Mañana, M

    2008-09-01

    In this work, the waste from 10 forest species of Cantabria have been characterized from the point of view of energy. The studied species were the waste of: Eucalyptus globulus, Eucalyptus nitens, the hybrid E. globulusxE. nitens, Eucalyptus viminalis, Eucalyptus smithii, Eucalyptus regnans, Eucalyptus gunni, Fagus sylvatica, Quercus robur and Pinus radiata. The leaves were the tree part with the greatest NCV (net calorific value) in all the species. The best results were obtained for the leaves of E. smithii (24.5 MJ/kg), F. sylvatica (22.8 MJ/kg) and E. nitens (22.5 MJ/kg), at minimum moisture. Values around 65,000 MJ per hectare and year were obtained for the Eucalyptus spp., and 47,000 MJ per hectare and year for the P. radiata. The economic-environmental analysis revealed that the use of the forest waste for energy production would mean an approximate annual income of 8 Meuro and would fix the annual CO(2) emitted by the Cantabrian industries at 78%.

  15. Temperature Range Shifts for Three European Tree Species over the Last 10,000 Years

    PubMed Central

    Cheddadi, Rachid; Araújo, Miguel B.; Maiorano, Luigi; Edwards, Mary; Guisan, Antoine; Carré, Matthieu; Chevalier, Manuel; Pearman, Peter B.

    2016-01-01

    We quantified the degree to which the relationship between the geographic distribution of three major European tree species, Abies alba, Fagus sylvatica and Picea abies and January temperature (Tjan) has remained stable over the past 10,000 years. We used an extended data-set of fossil pollen records over Europe to reconstruct spatial variation in Tjan values for each 1000-year time slice between 10,000 and 3000 years BP (before present). We evaluated the relationships between the occurrences of the three species at each time slice and the spatially interpolated Tjan values, and compared these to their modern temperature ranges. Our results reveal that F. sylvatica and P. abies experienced Tjan ranges during the Holocene that differ from those of the present, while A. alba occurred over a Tjan range that is comparable to its modern one. Our data suggest the need for re-evaluation of the assumption of stable climate tolerances at a scale of several thousand years. The temperature range instability in our observed data independently validates similar results based exclusively on modeled Holocene temperatures. Our study complements previous studies that used modeled data by identifying variation in frequencies of occurrence of populations within the limits of suitable climate. However, substantial changes that were observed in the realized thermal niches over the Holocene tend to suggest that predicting future species distributions should not solely be based on modern realized niches, and needs to account for the past variation in the climate variables that drive species ranges. PMID:27826308

  16. Perception of photoperiod in individual buds of mature trees regulates leaf-out.

    PubMed

    Zohner, Constantin M; Renner, Susanne S

    2015-12-01

    Experimental data on the perception of day length and temperature in dormant temperate zone trees are surprisingly scarce. In order to investigate when and where these environmental signals are perceived, we carried out bagging experiments in which buds on branches of Fagus sylvatica, Aesculus hippocastanum and Picea abies trees were exposed to natural light increase or kept at constant 8-h days from December until June. Parallel experiments used twigs cut from the same trees, harvesting treated and control twigs seven times and then exposing them to 8- or 16-h days in a glasshouse. Under 8-h days, budburst in Fagus outdoors was delayed by 41 d and in Aesculus by 4 d; in Picea, day length had no effect. Buds on nearby branches reacted autonomously, and leaf primordia only reacted to light cues in late dormancy after accumulating warm days. Experiments applying different wavelength spectra and high-resolution spectrometry to buds indicate a phytochrome-mediated photoperiod control. By demonstrating local photoperiodic control of buds, revealing the time when these signals are perceived, and showing the interplay between photoperiod and chilling, this study contributes to improved modelling of the impact of climate warming on photosensitive species.

  17. Coordination between growth, phenology and carbon storage in three coexisting deciduous tree species in a temperate forest.

    PubMed

    Klein, Tamir; Vitasse, Yann; Hoch, Günter

    2016-07-01

    In deciduous trees growing in temperate forests, bud break and growth in spring must rely on intrinsic carbon (C) reserves. Yet it is unclear whether growth and C storage occur simultaneously, and whether starch C in branches is sufficient for refoliation. To test in situ the relationships between growth, phenology and C utilization, we monitored stem growth, leaf phenology and stem and branch nonstructural carbohydrate (NSC) dynamics in three deciduous species: Carpinus betulus L., Fagus sylvatica L. and Quercus petraea (Matt.) Liebl. To quantify the role of NSC in C investment into growth, a C balance approach was applied. Across the three species, >95% of branchlet starch was consumed during bud break, confirming the importance of C reserves for refoliation in spring. The C balance calculation showed that 90% of the C investment in foliage (7.0-10.5 kg tree(-1) and 5-17 times the C needed for annual stem growth) was explained by simultaneous branchlet starch degradation. Carbon reserves were recovered sooner than expected, after leaf expansion, in parallel with stem growth. Carpinus had earlier leaf phenology (by ∼25 days) but delayed cambial growth (by ∼15 days) than Fagus and Quercus, the result of a competitive strategy to flush early, while having lower NSC levels.

  18. Expanding leaves of mature deciduous forest trees rapidly become autotrophic.

    PubMed

    Keel, Sonja G; Schädel, Christina

    2010-10-01

    Emerging leaves in evergreen tree species are supplied with carbon (C) from the previous year's foliage. In deciduous trees, no older leaves are present, and the early phase of leaf development must rely on C reserves from other tissues. How soon developing leaves become autotrophic and switch from being C sinks to sources has rarely been studied in mature forest trees, and simultaneous comparisons of species are scarce. Using a canopy crane and a simple (13)CO(2)-pulse-labelling technique, we demonstrate that young leaves of mature trees in three European deciduous species (Fagus sylvatica L., Quercus petraea (Matt.) Liebl., Tilia platyphyllos Scop.) start assimilating CO(2) at a very early stage of development (10-50% expanded). One month after labelling, all leaves were still strongly (13)C enriched, suggesting that recent photosynthates had been incorporated into slow turnover pools such as cellulose or lignin and thus had contributed to leaf growth. In line with previous studies performed at the same site, we found stronger incorporation of recent photosynthates into growing tissues of T. platyphyllos compared with F. sylvatica and Q. petraea. Non-structural carbohydrate (NSC) concentrations analysed for one of the three study species (F. sylvatica) showed that sugar and starch pools rapidly increased during leaf development, suggesting that newly developed leaves soon produce more NSC than can be used for growth. In conclusion, our findings indicate that expanding leaves of mature deciduous trees become C autonomous at an early stage of development despite the presence of vast amounts of mobile carbohydrate reserves.

  19. Assessing the long-term species composition predicted by PrognAus

    PubMed Central

    Huber, Markus O.

    2010-01-01

    Tree growth models are supposed to contain stand growth laws as so called “emergent properties” which derive from interactions of individual-tree growth and mortality functions. This study investigates whether the evolving tree species composition in a long term simulation by the distance-independent tree growth model PrognAus matches the species composition of the potential natural vegetation type which is expected to occur if one refrains from further management interventions and major disturbances, climate change, and changes in site conditions can be excluded. For this purpose the development of 6933 sample plots of the Austrian National Forest Inventory was predicted for 2500 years. The resulting species proportions, derived from volume per hectare of 15 tree species or species groups, were used to classify every sample plot according to potential natural forest types, following a classification scheme based on expert knowledge. These simulated potential natural vegetation types were compared with expert reconstructions of the sample plots of the Austrian National Forest Inventory. A total of 5789 plots were actually classified with the scheme; in 33% of the cases the classification on the basis of the PrognAus-simulations was identical with the classification by the Austrian National Forest Inventory. A predominantly correct classification was achieved for the subalpine Picea abies-type and the Fagus sylvatica-type although PrognAus showed a tendency to overestimate the proportion of F. sylvatica and P. abies. Weaknesses in the ability to simulate forest types dominated by Quercus spp., Acer spp., and Pinus sylvestris were identified. This shortcoming might be caused by the mortality model which allows a larger diameter at breast height for F. sylvatica or by the ingrowth model whose terms for the consideration of inter-specific competition may lead to a disadvantage of Quercus spp., P. sylvestris, and Abies alba. Moreover, the ingrowth model might be

  20. Molecular Profiling of the Phytophthora plurivora Secretome: A Step towards Understanding the Cross-Talk between Plant Pathogenic Oomycetes and Their Hosts

    PubMed Central

    Fleischmann, Frank; Dalio, Ronaldo J. D.; Di Maro, Antimo; Scognamiglio, Monica; Fiorentino, Antonio; Parente, Augusto; Osswald, Wolfgang; Chambery, Angela

    2014-01-01

    The understanding of molecular mechanisms underlying host–pathogen interactions in plant diseases is of crucial importance to gain insights on different virulence strategies of pathogens and unravel their role in plant immunity. Among plant pathogens, Phytophthora species are eliciting a growing interest for their considerable economical and environmental impact. Plant infection by Phytophthora phytopathogens is a complex process coordinated by a plethora of extracellular signals secreted by both host plants and pathogens. The characterization of the repertoire of effectors secreted by oomycetes has become an active area of research for deciphering molecular mechanisms responsible for host plants colonization and infection. Putative secreted proteins by Phytophthora species have been catalogued by applying high-throughput genome-based strategies and bioinformatic approaches. However, a comprehensive analysis of the effective secretome profile of Phytophthora is still lacking. Here, we report the first large-scale profiling of P. plurivora secretome using a shotgun LC-MS/MS strategy. To gain insight on the molecular signals underlying the cross-talk between plant pathogenic oomycetes and their host plants, we also investigate the quantitative changes of secreted protein following interaction of P. plurivora with the root exudate of Fagus sylvatica which is highly susceptible to the root pathogen. We show that besides known effectors, the expression and/or secretion levels of cell-wall-degrading enzymes were altered following the interaction with the host plant root exudate. In addition, a characterization of the F. sylvatica root exudate was performed by NMR and amino acid analysis, allowing the identification of the main released low-molecular weight components, including organic acids and free amino acids. This study provides important insights for deciphering the extracellular network involved in the highly susceptible P. plurivora-F. sylvatica interaction

  1. Molecular profiling of the Phytophthora plurivora secretome: a step towards understanding the cross-talk between plant pathogenic oomycetes and their hosts.

    PubMed

    Severino, Valeria; Farina, Annarita; Fleischmann, Frank; Dalio, Ronaldo J D; Di Maro, Antimo; Scognamiglio, Monica; Fiorentino, Antonio; Parente, Augusto; Osswald, Wolfgang; Chambery, Angela

    2014-01-01

    The understanding of molecular mechanisms underlying host-pathogen interactions in plant diseases is of crucial importance to gain insights on different virulence strategies of pathogens and unravel their role in plant immunity. Among plant pathogens, Phytophthora species are eliciting a growing interest for their considerable economical and environmental impact. Plant infection by Phytophthora phytopathogens is a complex process coordinated by a plethora of extracellular signals secreted by both host plants and pathogens. The characterization of the repertoire of effectors secreted by oomycetes has become an active area of research for deciphering molecular mechanisms responsible for host plants colonization and infection. Putative secreted proteins by Phytophthora species have been catalogued by applying high-throughput genome-based strategies and bioinformatic approaches. However, a comprehensive analysis of the effective secretome profile of Phytophthora is still lacking. Here, we report the first large-scale profiling of P. plurivora secretome using a shotgun LC-MS/MS strategy. To gain insight on the molecular signals underlying the cross-talk between plant pathogenic oomycetes and their host plants, we also investigate the quantitative changes of secreted protein following interaction of P. plurivora with the root exudate of Fagus sylvatica which is highly susceptible to the root pathogen. We show that besides known effectors, the expression and/or secretion levels of cell-wall-degrading enzymes were altered following the interaction with the host plant root exudate. In addition, a characterization of the F. sylvatica root exudate was performed by NMR and amino acid analysis, allowing the identification of the main released low-molecular weight components, including organic acids and free amino acids. This study provides important insights for deciphering the extracellular network involved in the highly susceptible P. plurivora-F. sylvatica interaction.

  2. Photoperiod and temperature responses of bud swelling and bud burst in four temperate forest tree species.

    PubMed

    Basler, David; Körner, Christian

    2014-04-01

    Spring phenology of temperate forest trees is optimized to maximize the length of the growing season while minimizing the risk of freezing damage. The release from winter dormancy is environmentally mediated by species-specific responses to temperature and photoperiod. We investigated the response of early spring phenology to temperature and photoperiod at different stages of dormancy release in cuttings from four temperate tree species in controlled environments. By tracking bud development, we were able to identify the onset of bud swelling and bud growth in Acer pseudoplatanus L., Fagus sylvatica L., Quercus petraea (Mattuschka) Liebl. and Picea abies (L.) H. Karst. At a given early stage of dormancy release, the onset and duration of the bud swelling prior to bud burst are driven by concurrent temperature and photoperiod, while the maximum growth rate is temperature dependent only, except for Fagus, where long photoperiods also increased bud growth rates. Similarly, the later bud burst was controlled by temperature and photoperiod (in the photoperiod sensitive species Fagus, Quercus and Picea). We conclude that photoperiod is involved in the release of dormancy during the ecodormancy phase and may influence bud burst in trees that have experienced sufficient chilling. This study explored and documented the early bud swelling period that precedes and defines later phenological stages such as canopy greening in conventional phenological works. It is the early bud growth resumption that needs to be understood in order to arrive at a causal interpretation and modelling of tree phenology at a large scale. Classic spring phenology events mark visible endpoints of a cascade of processes as evidenced here.

  3. Comparison of budburst dynamics between species on altitudinal gradient

    NASA Astrophysics Data System (ADS)

    Davi, H.; Gillmann, M.; Ibanez, T.

    2009-04-01

    Phenology of plants is a key ecosystem parameter controlling carbon and water fluxes and also acting on the dynamics of communities. This parameter is highly sensitive to the climate and consequently is often used as a proxy of global change. In this paper, we attempt to analyse the dynamics of budburst every week for seven species (Fagus sylvatica L., Acer opalus Mill , Sorbus aria L., Quercus pubescens Willd. Abies alba Mill., Pinus sylvestris L., Pinus nigra Arnold) in two altitudinal gradients, one in a northern slope and one in a southern slope in the Ventoux mountain. The originality of this work is to assess not only the budburst date but to more precisely analyse the dynamics of budburst and its variation with altitude according to the species. Two important results are highlighted. First, the dynamics of budburst changes according to the species. Three distinct patterns can be drawn, a rapid sigmoid increase for the deciduous species, a short sigmoid increase for the pines and an intermediate curve for silver fir. These dynamics can be slowing down for coniferous when frost arises during the budburst. The second topic is the link between budburst and temperature by analysing respectively the year, the altitudinal and the aspect (north and south) effects. In 2007, budburst occurs earlier for Fagus, Acer, and Abies, it does not change for pines and is delayed for Sorbus. Date of beech budburst is the same between north and south in spite of higher temperature in south. The altitude effect on budburst varies greatly according to species and the year with a weak effect on Fagus and a stronger effect for the others species showing a threshold at 1200 m. By analysing the mean of temperatures at each altitude, we conclude that temperature effect acts differently between years or between altitudes. To conclude, we highlighted the complex effect of temperatures on budburst varying between species and situations.

  4. Canopy carbon budget of Siebold's beech (Fagus crenata) sapling under free air ozone exposure.

    PubMed

    Watanabe, Makoto; Hoshika, Yasutomo; Inada, Naoki; Koike, Takayoshi

    2014-01-01

    To determine the effects of ozone (O3) on the canopy carbon budget, we investigated photosynthesis and respiration of leaves of Siebold's beech saplings under free air O3 exposure (60 nmol mol(-1), during daytime) in relation to the within-canopy light gradient; we then calculated the canopy-level photosynthetic carbon gain (PCG) and respiratory carbon loss (RCL) using a canopy photosynthesis model. Susceptibilities of photosynthesis and respiration to O3 were greater in leaves of upper canopy than in the lower canopy. The canopy net carbon gain (NCG) was reduced by O3 by 12.4% during one growing season. The increased RCL was the main factor for the O3-induced reduction in NCG in late summer, while contributions of the reduced PCG and the increased RCL to the NCG were almost the same in autumn. These results indicate contributions of changes in PCG and RCL under O3 to NCG were different between seasons.

  5. Role of intracellular contents to facilitate supercooling capability in beech (Fagus crenata) xylem parenchyma cells.

    PubMed

    Kasuga, Jun; Mizuno, Kaoru; Miyaji, Natsuko; Arakawa, Keita; Fujikawa, Seizo

    2006-01-01

    In order to find the possible role of intracellular contents in facilitating the supercooling capability of xylem parenchyma cells, changes in the temperature of supercooling levels were compared before and after the release of intracellular substances from beech xylem parenchyma cells by DTA. Various methods were employed to release intracellular substances from xylem parenchyma cells and all resulted in a reduction of supercooling ability. It was concluded that the reduction of supercooling ability primarily resulted from changes of intracellular conditions, including the release of intracellular contents or their mixing with extracellular solutions, rather than due to changes of cell wall structures. It is therefore suggested that any unidentified intracellular contents may function to facilitate supercooling capability in xylem parenchyma cells.

  6. In-situ carbon and nitrogen turnover dynamics and the role of soil functional biodiversity therein; a climate warming simulation study in Alpine ecosystems

    NASA Astrophysics Data System (ADS)

    Djukic, Ika

    2010-05-01

    Climate change affects a variety of soil properties and processes. Alpine soils take an extraordinary position in this context because of the vulnerability of mountain regions to climatic changes. We used altitudinal soil translocation to simulate the combined effects of changing climatic conditions and shifting vegetation zones in order to study short- to medium-term soil changes in the Austrian Limestone Alps. We translocated 160 soil cores from an alpine grassland site (1900 m asl) down to a sub-alpine spruce forest (1300 m asl) and a montane beech forest site (900m asl), including reference soil cores at each site to estimate artifacts arising from the method. 15N-labeled maize straw was added (1 kg/m2) to translocated and control soil cores and sampled over a period of 2 years for the analysis of δ13C and δ15N in the bulk soil and extracted phospholipid fatty acids (PLFAs). Additionally, 20 litter bags (at each of the three climatic zones) containing Fagus sylvatica or Pinus nigra litter were inserted into the soil, and decomposition was studied over a two-year period. The basic soil parameters (organic C, total N and pH) were unaffected by translocation within the observation time. Overall, decomposition of Pinus nigra litter was significantly slower compared to Fagus sylvatica, and the decomposition rate of both litter types was inversely related to elevation. The decomposition of the maize straw carbon was significantly faster in the translocated soil cores (sites at 900 and 1300 m asl) than at the original site (1900 m asl). The labelled nitrogen contents in the translocated soil cores showed just marginal differences to the soil cores at the original site. The maize straw application promptly increased the amount of bacterial and fungal PLFAs at all studied sites. Downslope translocated soil cores showed an increase in total microbial biomass and sum of bacteria. The fungal PLFA biomarker 18:2ω6,9 was slightly lower at the new (host) sites compared to

  7. Comparison of the carbon stock in forest soil of sessile oak and beech forests

    NASA Astrophysics Data System (ADS)

    Horváth, Adrienn; Bene, Zsolt; Bidló, András

    2016-04-01

    Forest ecosystems are the most important carbon sinks. The forest soils play an important role in the global carbon cycle, because the global climate change or the increase of atmospheric CO2 level. We do not have enough data about the carbon stock of soils and its change due to human activities, which have similar value to carbon content of biomass. In our investigation we measured the carbon stock of soil in 10 stands of Quercus petraea and Fagus sylvatica. We took a 1.1 m soil column with soil borer and divided to 11 samples each column. The course organic and root residues were moved. After evaluation, we compared our results with other studies and the carbon stock of forests to each other. Naturally, the amount of SOC was the highest in the topsoil layers. However, we found significant difference between forest stands which stayed on the same homogenous bedrock, but very close to each other (e.g. distance was 1 or 2 km). We detected that different forest utilizations and tree species have an effect on the forest carbon as the litter as well (amount, composition). In summary, we found larger amount (99.1 C t/ha on average) of SOC in soil of stands, where sessile oak were the main stand-forming tree species. The amount of carbon was the least in turkey oak-sessile oak stands (85.4 C t/ha on average). We found the highest SOC (118.3 C t/ha) in the most mixed stand (silver lime-beech-red oak). In the future, it will be very important: How does climate change affect the spread of tree species or on carbon storage? Beech is more sensitive, but even sessile oak. These species are expected to replace with turkey oak, which is less sensitive to drought. Thus, it is possible in the future that we can expect to decrease of forest soil carbon stock capacity, which was confirmed by our experiment. Keywords: carbon sequestration, mitigation, Fagus sylvatica, Quercus petraea, litter Acknowledgements: Research is supported by the "Agroclimate.2" (VKSZ_12-1-2013-0034) EU

  8. The potential of beech seedlings to adapt to low P availability in soil - plant versus microbial effects on P mobilising potential in the rhizosphere

    NASA Astrophysics Data System (ADS)

    Meller, Sonia; Frey, Beat; Frossard, Emmanuel; Spohn, Marie; Schack-Kirchner, Helmer; Luster, Jörg

    2016-04-01

    The objective of our work was to investigate to what extent tree seedlings (Fagus sylvatica) are able to adapt the process of P mobilisation in the rhizosphere according to P speciation in the soil. Such mobilisation activity can include root exudation of P mobilising compounds or stimulation of specific P mobilising soil microbes. We hypothesized that Fagus sylvatica seedlings can adapt their own activity based on their P nutritional status and genetic memory of how to react under a given nutritional situation. To test the hypothesis, we set up a cross-growth experiment with beech of different provenances growing in soil from their own provenance site and in soil differing in P availability. Experiments were performed as a greenhouse experiment, with temperature control and natural light, during one vegetation period in rhizoboxes . We used two acidic forest soils, contrasting in P availability, collected at field sites of the German research priority program "Ecosystem Nutrition". Juvenile trees were collected along with the soils at the sites and planted respectively. The occurrence of P mobilising compounds and available P in the rhizosphere and in bulk soil were measured during the active growth season of the plants. In particular, we assessed phosphatase activity, (measured with zymography and plate enzymatic assay at pH 4,6.5, and 11) carboxylates and phosphate (measured by application of ion exchange membranes to specific soil micro zones, and by microdialysis), and pH (mapping with optodes). Plant P nutrition status was assessed by total P, N/P, phosphatase activity, and metabolic (TCA extractable) P in the leaves. The P-nutritional status of the beech provenances differed markedly independent from the P status of the soil where they were actually grown during experiment. In particular, the juvenile trees from the site rich in mineral P were sufficient in P, while those from the P-poor site with mostly organic P, were deficient. Enzymatic activity at the

  9. A Late Holocene environmental history of a bat guano deposit from Romania: an isotopic, pollen and microcharcoal study

    NASA Astrophysics Data System (ADS)

    Forray, Ferenc L.; Onac, Bogdan P.; Tanţău, Ioan; Wynn, Jonathan G.; Tămaş, Tudor; Coroiu, Ioan; Giurgiu, Alexandra M.

    2015-11-01

    A 1.5-m-long core from a bat guano deposit in Zidită Cave (western Romania) has provided a 900-year record of environmental change. Shifts in δ13C values of bulk guano (between -22.6 and -27.5‰) combined with guano-sourced pollen and microcharcoal information show significant changes in the structure of vegetation and plant biomass. Cave guano δ13C values reflect the dietary preferences of bats which are controlled by local vegetation dynamics, which in turn depend on local climatic conditions. Neither δ13C values nor pollen association in guano changed strikingly over the Medieval Warm Period (MWP) and Little Ice Age (LIA) transition. Instead, an overall decreasing trend of δ13C values between ca. AD 1200 and 1870-1900 defines the duration of LIA. A shift toward cooler and wetter conditions at ca. AD 1500 noticed in the pollen record by an increase in Fagus sylvatica and Alnus and the decrease of Carpinus betulus, may indicate the first major change at the beginning of the LIA. Evidence for two major cold spells occurring around AD 1500 and ca. AD 1870 comes from both δ13C and pollen record. In between these events, the cave region experienced a warmer and drier climate but colder and wetter than the MWP, favouring the expansion of Quercus, Fraxinus and Tilia simultaneously with the decrease of F. sylvatica and Poaceae. Human impact in the studied area is mainly related to agriculture, grazing and deforestation. The effects are most pronounced after AD 1845 when the pollen of cereals increases and Zea is recorded (AD 1845). Higher percentages of microcharcoal particles in the guano sequence are generally correlated with agricultural activities like land cleaning via controlled fires.

  10. Facilitative-Competitive Interactions in an Old-Growth Forest: The Importance of Large-Diameter Trees as Benefactors and Stimulators for Forest Community Assembly

    PubMed Central

    Fichtner, Andreas; Forrester, David I.; Härdtle, Werner; Sturm, Knut; von Oheimb, Goddert

    2015-01-01

    The role of competition in tree communities is increasingly well understood, while little is known about the patterns and mechanisms of the interplay between above- and belowground competition in tree communities. This knowledge, however, is crucial for a better understanding of community dynamics and developing adaptive near-natural management strategies. We assessed neighbourhood interactions in an unmanaged old-growth European beech (Fagus sylvatica) forest by quantifying variation in the intensity of above- (shading) and belowground competition (crowding) among dominant and co-dominant canopy beech trees during tree maturation. Shading had on average a much larger impact on radial growth than crowding and the sensitivity to changes in competitive conditions was lowest for crowding effects. We found that each mode of competition reduced the effect of the other. Increasing crowding reduced the negative effect of shading, and at high levels of shading, crowding actually had a facilitative effect and increased growth. Our study demonstrates that complementarity in above- and belowground processes enable F. sylvatica to alter resource acquisition strategies, thus optimising tree radial growth. As a result, competition seemed to become less important in stands with a high growing stock and tree communities with a long continuity of anthropogenic undisturbed population dynamics. We suggest that growth rates do not exclusively depend on the density of potential competitors at the intraspecific level, but on the conspecific aggregation of large-diameter trees and their functional role for regulating biotic filtering processes. This finding highlights the potential importance of the rarely examined relationship between the spatial aggregation pattern of large-diameter trees and the outcome of neighbourhood interactions, which may be central to community dynamics and the related forest ecosystem services. PMID:25803035

  11. Fruit production in three masting tree species does not rely on stored carbon reserves.

    PubMed

    Hoch, Günter; Siegwolf, Rolf T W; Keel, Sonja G; Körner, Christian; Han, Qingmin

    2013-03-01

    Fruiting is typically considered to massively burden the seasonal carbon budget of trees. The cost of reproduction has therefore been suggested as a proximate factor explaining observed mast-fruiting patterns. Here, we used a large-scale, continuous (13)C labeling of mature, deciduous trees in a temperate Swiss forest to investigate to what extent fruit formation in three species with masting reproduction behavior (Carpinus betulus, Fagus sylvatica, Quercus petraea) relies on the import of stored carbon reserves. Using a free-air CO2 enrichment system, we exposed trees to (13)C-depleted CO2 during 8 consecutive years. By the end of this experiment, carbon reserve pools had significantly lower δ(13)C values compared to control trees. δ(13)C analysis of new biomass during the first season after termination of the CO2 enrichment allowed us to distinguish the sources of built-in carbon (old carbon reserves vs. current assimilates). Flowers and expanding leaves carried a significant (13)C label from old carbon stores. In contrast, fruits and vegetative infructescence tissues were exclusively produced from current, unlabeled photoassimilates in all three species, including F. sylvatica, which had a strong masting season. Analyses of δ(13)C in purified starch from xylem of fruit-bearing shoots revealed a complete turn-over of starch during the season, likely due to its usage for bud break. This study is the first to directly demonstrate that fruiting is independent from old carbon reserves in masting trees, with significant implications for mechanistic models that explain mast seeding.

  12. Facilitative-competitive interactions in an old-growth forest: the importance of large-diameter trees as benefactors and stimulators for forest community assembly.

    PubMed

    Fichtner, Andreas; Forrester, David I; Härdtle, Werner; Sturm, Knut; von Oheimb, Goddert

    2015-01-01

    The role of competition in tree communities is increasingly well understood, while little is known about the patterns and mechanisms of the interplay between above- and belowground competition in tree communities. This knowledge, however, is crucial for a better understanding of community dynamics and developing adaptive near-natural management strategies. We assessed neighbourhood interactions in an unmanaged old-growth European beech (Fagus sylvatica) forest by quantifying variation in the intensity of above- (shading) and belowground competition (crowding) among dominant and co-dominant canopy beech trees during tree maturation. Shading had on average a much larger impact on radial growth than crowding and the sensitivity to changes in competitive conditions was lowest for crowding effects. We found that each mode of competition reduced the effect of the other. Increasing crowding reduced the negative effect of shading, and at high levels of shading, crowding actually had a facilitative effect and increased growth. Our study demonstrates that complementarity in above- and belowground processes enable F. sylvatica to alter resource acquisition strategies, thus optimising tree radial growth. As a result, competition seemed to become less important in stands with a high growing stock and tree communities with a long continuity of anthropogenic undisturbed population dynamics. We suggest that growth rates do not exclusively depend on the density of potential competitors at the intraspecific level, but on the conspecific aggregation of large-diameter trees and their functional role for regulating biotic filtering processes. This finding highlights the potential importance of the rarely examined relationship between the spatial aggregation pattern of large-diameter trees and the outcome of neighbourhood interactions, which may be central to community dynamics and the related forest ecosystem services.

  13. Light-mediated K(leaf) induction and contribution of both the PIP1s and PIP2s aquaporins in five tree species: walnut (Juglans regia) case study.

    PubMed

    Baaziz, Khaoula Ben; Lopez, David; Rabot, Amelie; Combes, Didier; Gousset, Aurelie; Bouzid, Sadok; Cochard, Herve; Sakr, Soulaiman; Venisse, Jean-Stephane

    2012-04-01

    Understanding the response of leaf hydraulic conductance (K(leaf)) to light is a challenge in elucidating plant-water relationships. Recent data have shown that the effect of light on K(leaf) is not systematically related to aquaporin regulation, leading to conflicting conclusions. Here we investigated the relationship between light, K(leaf), and aquaporin transcript levels in five tree species (Juglans regia L., Fagus sylvatica L., Quercus robur L., Salix alba L. and Populus tremula L.) grown in the same environmental conditions, but differing in their K(leaf) responses to light. Moreover, the K(leaf) was measured by two independent methods (high-pressure flow metre (HPFM) and evaporative flux method (EFM)) in the most (J. regia) and least (S. alba) responsive species and the transcript levels of aquaporins were analyzed in perfused and unperfused leaves. Here, we found that the light-induced K(leaf) value was closely related to stronger expression of both the PIP1 and PIP2 aquaporin genes in walnut (J. regia), but to stimulation of PIP1 aquaporins alone in F. sylvatica and Q. robur. In walnut, all newly identified aquaporins were found to be upregulated in the light and downregulated in the dark, further supporting the relationship between the light-mediated induction of K(leaf) and aquaporin expression in walnut. We also demonstrated that the K(leaf) response to light was quality-dependent, K(leaf) being 60% lower in the absence of blue light. This decrease in K(leaf) was correlated with strong downregulation of three PIP2 aquaporins and of all the PIP1 aquaporins tested. These data support a relationship between light-mediated K(leaf) regulation and the abundance of aquaporin transcripts in the walnut tree.

  14. Classifying Oriental Beech (Fagus orientalis Lipsky.) Forest Sites Using Direct, Indirect and Remote Sensing Methods: A Case Study from Turkey

    PubMed Central

    Günlü, Alkan; Baskent, Emin Zeki; Kadiogullari, Ali İhsan; Ercanli, İlker

    2008-01-01

    Determining the productivity of forest sites through various classification techniques is important for making appropriate forest management decisions. Forest sites were classified using direct and indirect (site index) and remote sensing (Landsat 7 ETM and Quickbird satellite image) methods. In the direct method, forest site classifications were assigned according to edafic (soil properties), climate (precipitation and temperature) and topographic (altitude, slope, aspect and landform) factors. Five different forest site classes (dry, moderate fresh, fresh, moist and highly moist) were determined. In the indirect method, the guiding curve was used to generate anamorphic site index (SI) equations resulting in three classes; good (SI=I-II), medium (SI=III) and poor (SI=IV-V). Forest sites were also determined with a remote sensing method (RSM) using supervised classification of Landsat 7 ETM and Quickbird satellite images with a 0.67 kappa statistic value and 73.3% accuracy assessments; 0.88 kappa statistic value and 90.7% accuracy assessments, respectively. Forest sites polygon themes obtained from the three methods were overlaid and areas in the same classes were computed with Geographic Information Systems (GIS). The results indicated that direct and SI methods were consistent as a 3% dry site (19.0 ha) was exactly determined by both the direct and SI methods as a site class IV. Comparison of SI and RMS methods indicated a small difference as the area was highly homogeneous and unmanaged. While 15.4 ha area (open and degraded areas) was not determined by SI but RSM. A 19.0 ha (100%) poor site was determined by the SI method, 14.9 ha (78%) poor site was in Landsat 7 ETM satellite image and 17.4 ha (92%) poor site in Quickbird satellite image. The relationship between direct and SI methods were statistically analyzed using chi-square test. The test indicated a statistically significant relationships between forest sites determined by direct method and Quicbird satellite image (χ2 = 36.794; df = 16; p = 0.002), but no significant relationships with Landsat 7 ETM satellite image (χ2 = 22.291; df = 16; p = 0.134). Moderate association was found between SI method and direct method (χ2 = 16.724; df = 8; p = 0.033). PMID:27879833

  15. Effects of dry ice on gas permeability of nano-silver-impregnated Populus nigra and Fagus orientalis.

    PubMed

    Taghiyari, H R; Layeghi, M; Aminzadeh Liyafooee, F

    2012-06-01

    Effects of dry-ice treatment (frozen CO(2) at -78.5°C) on gas permeability of untreated and nano-silver-impregnated poplar and beech specimens were studied here on the basis of their biological structure and woody mass as well as their vessel element types. A 200 ppm aqueous dispersion of silver nano-particles was used for impregnation; the size range of silver nano-particles was 20-80 nm. Dry-ice treatment increased gas permeability by 87 and 45% in poplar and beech, respectively. Nano-silver impregnation also increased gas permeability by 190 and 89% in poplar and beech, respectively. Dry-ice treatment on nano-silver-impregnated specimens increased gas permeability even more (31% increase in poplar but only 0.96% in beech). It may be concluded that dry-ice treatment on solid woods may be used as a practical method to increase permeability in species that because of their biological structures are impermeable; since this method alters the biological structure slightly and consequently decreases mechanical strength of solid woods insignificantly, it may substitute methods such as incising to increase permeability.

  16. High-resolution isotope measurements resolve rapid ecohydrological dynamics at the soil-plant interface.

    PubMed

    Volkmann, Till H M; Haberer, Kristine; Gessler, Arthur; Weiler, Markus

    2016-05-01

    Plants rely primarily on rainfall infiltrating their root zones - a supply that is inherently variable, and fluctuations are predicted to increase on most of the Earth's surface. Yet, interrelationships between water availability and plant use on short timescales are difficult to quantify and remain poorly understood. To overcome previous methodological limitations, we coupled high-resolution in situ observations of stable isotopes in soil and transpiration water. We applied the approach along with Bayesian mixing modeling to track the fate of (2) H-labeled rain pulses following drought through soil and plants of deciduous tree ecosystems. We resolve how rainwater infiltrates the root zones in a nonequilibrium process and show that tree species differ in their ability to quickly acquire the newly available source. Sessile oak (Quercus petraea) adjusted root uptake to vertical water availability patterns under drought, but readjustment toward the rewetted topsoil was delayed. By contrast, European beech (Fagus sylvatica) readily utilized water from all soil depths independent of water depletion, enabling faster uptake of rainwater. Our results demonstrate that species-specific plasticity and responses to water supply fluctuations on short timescales can now be identified and must be considered to predict vegetation functional dynamics and water cycling under current and future climatic conditions.

  17. Influence of Climatic Type of Year on Beech and Scots Pine Eustress

    NASA Astrophysics Data System (ADS)

    Lyubenova, Mariyana; Chikalanov, Alexandre; van Bodegom, Peter; Kattge, Jens; Popova, Silvia; Zlateva, Plamena

    2016-04-01

    The present study deals with the relationships of climate types and the periods with low radial stem growth of black pine and beech locations in Europe. The identification of climatic types (CT) and eustress caused CT, their relative participation in the period of 1901-2009 by locations, the manifestation of main adverse type, led periodically to reduction of tree ring width, as well as the comparison of obtained types by precipitations and the SPI classes were the subjects of investigation. The analyses demonstrated that despite the local differences, the stress impact of dry and wet years, especially if they are accompanied by the cold or hot regimes, is well expressed. The successive changes of climate types at least two years before the eustress year are also relevant. The application of climatic types to study the relationship with trees eustress is more applicable when there are no large deviations in temperatures or precipitations by years and locations. The demonstrated holistic analyses are applicable for the forest areas monitoring and management. Key words Pinus sylvestris L., Fagus sylvatica L., climatic type, SPI, eustress, SPPAM application, SPI

  18. Physical and Chemical Properties of Some Imported Woods and their Degradation by Termites

    PubMed Central

    Shanbhag, Rashmi R.; Sundararaj, R.

    2013-01-01

    The influence of physical and chemical properties of 20 species of imported wood on degradation of the wood by termites under field conditions was studied. The wood species studied were: Sycamore maple, Acer pseudoplatanus L. (Sapindales: Sapindaceae) (from two countries), Camphor, Dryobalanops aromatic C.F.Gaertner (Malvales: Dipterocarpaceae), Beech, Fagus grandifolia Ehrhart (Fagales: Fagaceae), F. sylvatica L. (from two countries), Oak, Quercus robur L., Ash, Fraxinus angustifolia Vahl (Lamiales: Oleaceae), F. excelsior L., Padauk, Pterocarpus soyauxii Taubert (Fabales: Fabaceae), (from two countries), Jamba, Xylia dolabrifiormis Roxburgh, Shorea laevis Ridley (Malvales: Dipterocarpaceae), S. macoptera Dyer, S. robusta Roth, Teak, Tectona grandis L.f. (Lamiales: Lamiaceae) (from five countries), and rubber tree, Hevea brasiliensis Müller Argoviensis (Malpighiales: Euphorbiaceae) from India. The termites present were: Odontotermes horni (Wasmann) (Isoptera: Termitidae), O. feae, O. wallonensis, and O. obeus (Rambur). A significant conelation was found between density, cellulose, lignin, and total phenolic contents of the wood and degradation by termites. The higher the density of the wood, the lower the degradation. Similarly, higher amount of lignin and total phenolic contents ensured higher resistance, whereas cellulose drives the termites towards the wood. PMID:23906349

  19. Segregation of nitrogen use between ammonium and nitrate of ectomycorrhizas and beech trees.

    PubMed

    Leberecht, Martin; Dannenmann, Michael; Tejedor, Javier; Simon, Judy; Rennenberg, Heinz; Polle, Andrea

    2016-12-01

    Here, we characterized nitrogen (N) uptake of beech (Fagus sylvatica) and their associated ectomycorrhizal (EM) communities from NH4(+) and NO3(-) . We hypothesized that a proportional fraction of ectomycorrhizal N uptake is transferred to the host, thereby resulting in the same uptake patterns of plants and their associated mycorrhizal communities. (15) N uptake was studied under various field conditions after short-term and long-term exposure to a pulse of equimolar NH4(+) and NO3(-) concentrations, where one compound was replaced by (15) N. In native EM assemblages, long-term and short-term (15) N uptake from NH4(+) was higher than that from NO3(-) , regardless of season, water availability and site exposure, whereas in beech long-term (15) N uptake from NO3(-) was higher than that from NH4(+) . The transfer rates from the EM to beech were lower for (15) N from NH4(+) than from NO3(-) . (15) N content in EM was correlated with (15) N uptake of the host for (15) NH4(+) , but not for (15) NO3(-) -derived N. These findings suggest stronger control of the EM assemblage on N provision to the host from NH4(+) than from NO3(-) . Different host and EM accumulation patterns for inorganic N will result in complementary resource use, which might be advantageous in forest ecosystems with limited N availability.

  20. How adaptable is the hydraulic system of European beech in the face of climate change-related precipitation reduction?

    PubMed

    Schuldt, Bernhard; Knutzen, Florian; Delzon, Sylvain; Jansen, Steven; Müller-Haubold, Hilmar; Burlett, Régis; Clough, Yann; Leuschner, Christoph

    2016-04-01

    Climate warming will increase the drought exposure of many forests world-wide. It is not well understood how trees adapt their hydraulic architecture to a long-term decrease in water availability. We examined 23 traits characterizing the hydraulic architecture and growth rate of branches and the dependent foliage of mature European beech (Fagus sylvatica) trees along a precipitation gradient (855-594 mm yr(-1) ) on uniform soil. A main goal was to identify traits that are associated with xylem efficiency, safety and growth. Our data demonstrate for the first time a linear increase in embolism resistance with climatic aridity (by 10%) across populations within a species. Simultaneously, vessel diameter declined by 7% and pit membrane thickness (Tm ) increased by 15%. Although specific conductivity did not change, leaf-specific conductivity declined by 40% with decreasing precipitation. Of eight plant traits commonly associated with embolism resistance, only vessel density in combination with pathway redundancy and Tm were related. We did not confirm the widely assumed trade-off between xylem safety and efficiency but obtained evidence in support of a positive relationship between hydraulic efficiency and growth. We conclude that the branch hydraulic system of beech has a distinct adaptive potential to respond to a precipitation reduction as a result of the environmental control of embolism resistance.

  1. Air pollution, precipitation chemistry and forest health in the Retezat Mountains, Southern Carpathians, Romania.

    PubMed

    Bytnerowicz, Andrzej; Badea, Ovidiu; Popescu, Flaviu; Musselman, Robert; Tanase, Mihai; Barbu, Ioan; Fraczek, Witold; Gembasu, Nicolae; Surdu, Aurelia; Danescu, Florin; Postelnicu, Daniela; Cenusa, Radu; Vasile, Cristian

    2005-10-01

    In the Retezat Mountains concentrations of O3, NO2 and SO2 in summer season 2000-2002 were low and below toxicity levels for forest trees. While NH3 concentrations were low in 2000, the 2001 and 2002 concentrations were elevated indicating possibility for increased N deposition to forest stands. More than 90% of the rain events were acidic with pH values <5.5, contributing to increased acidity of soils. Crown condition of Norway spruce (Picea abies) and European beech (Fagus sylvatica) was good, however, defoliation described as >25% of foliage injured increased from 9.1% in 2000 to 16.1% in 2002. Drought that occurred in the southern Carpathians between fall 2000 and summer 2002 and frequent acidic rainfalls could cause the observed decline of forest condition. Both Norway spruce and European beech with higher defoliation had lower annual radial increments compared to the trees with low defoliation. Ambient O3 levels found in the Retezat did not affect crown condition of Norway spruce or European beech.

  2. Using historical ecology to reassess the conservation status of coniferous forests in Central Europe.

    PubMed

    Szabó, Péter; Kuneš, Petr; Svobodová-Svitavská, Helena; Švarcová, Markéta Gabriela; Křížová, Lucie; Suchánková, Silvie; Müllerová, Jana; Hédl, Radim

    2017-02-01

    Forests cover approximately one-third of Central Europe. Oak (Quercus) and European beech (Fagus sylvatica) are considered the natural dominants at low and middle elevations, respectively. Many coniferous forests (especially of Picea abies) occur primarily at midelevations, but these are thought to have resulted from forestry plantations planted over the past 200 years. Nature conservation and forestry policy seek to promote broadleaved trees over conifers. However, there are discrepancies between conservation guidelines (included in Natura 2000) and historical and palaeoecological data with regard to the distribution of conifers. Our aim was to bring new evidence to the debate on the conservation of conifers versus broadleaved trees at midelevations in Central Europe. We created a vegetation and land-cover model based on pollen data for a highland area of 11,300 km(2) in the Czech Republic and assessed tree species composition in the forests before the onset of modern forestry based on 18th-century archival sources. Conifers dominated the study region throughout the entire Holocene (approximately 40-60% of the area). Broadleaved trees were present in a much smaller area than envisaged by current ideas of natural vegetation. Rather than casting doubt on the principles of Central European nature conservation in general, our results highlight the necessity of detailed regional investigations and the importance of historical data in challenging established notions on the natural distribution of tree species.

  3. Grazing by Folsomia candida (Collembola) differentially affects mycelial morphology of the cord-forming basidiomycetes Hypholoma fasciculare, Phanerochaete velutina and Resinicium bicolor.

    PubMed

    Tordoff, George M; Boddy, Lynne; Jones, T Hefin

    2006-03-01

    Cord-forming basidiomycetes are important decomposers of dead wood in forest ecosystems but the impact of mycophagous soil invertebrates on their mycelia are little known. Here we investigate the effects of different grazing intensities of Collembola (Folsomia candida) on mycelial foraging patterns of the saprotrophic cord-forming basidiomycetes Hypholoma fasciculare, Phanerochaete velutina and Resinicium bicolor growing from beech (Fagus sylvatica) wood block inocula in dishes of non-sterile soil. Mycelial extension rate and hyphal coverage decreased with increased grazing intensity. R. bicolor was most affected, high grazing density resulting in only a few major cords remaining. Grazing of H. fasciculare often resulted in points of more rapid outgrowth as cords with a fanned margin. In grazed mycelia of P. velutina the main cords had fanned tips and lateral cords became branched. These results suggest that mycophagy by Collembola may hinder the growth of cord-forming fungi in woodlands, which might impact on the ability of these fungi to forage for and decompose dead organic material.

  4. Simulating stand climate, phenology, and photosynthesis of a forest stand with a process-based growth model

    NASA Astrophysics Data System (ADS)

    Rötzer, Thomas; Leuchner, Michael; Nunn, Angela J.

    2010-07-01

    In the face of climate change and accompanying risks, forest management in Europe is becoming increasingly important. Model simulations can help to understand the reactions and feedbacks of a changing environment on tree growth. In order to simulate forest growth based on future climate change scenarios, we tested the basic processes underlying the growth model BALANCE, simulating stand climate (air temperature, photosynthetically active radiation (PAR) and precipitation), tree phenology, and photosynthesis. A mixed stand of 53- to 60-year-old Norway spruce ( Picea abies) and European beech ( Fagus sylvatica) in Southern Germany was used as a reference. The results show that BALANCE is able to realistically simulate air temperature gradients in a forest stand using air temperature measurements above the canopy and PAR regimes at different heights for single trees inside the canopy. Interception as a central variable for water balance of a forest stand was also estimated. Tree phenology, i.e. bud burst and leaf coloring, could be reproduced convincingly. Simulated photosynthesis rates were in accordance with measured values for beech both in the sun and the shade crown. For spruce, however, some discrepancies in the rates were obvious, probably due to changed environmental conditions after bud break. Overall, BALANCE has shown to respond to scenario simulations of a changing environment (e.g., climate change, change of forest stand structure).

  5. The effects of gap size on some microclimate variables during late summer and autumn in a temperate broadleaved deciduous forest.

    PubMed

    Abd Latif, Zulkiflee; Blackburn, George Alan

    2010-03-01

    The creation of gaps can strongly influence forest regeneration and habitat diversity within forest ecosystems. However, the precise characteristics of such effects depend, to a large extent, upon the way in which gaps modify microclimate and soil water content. Hence, the aim of this study was to understand the effects of gap creation and variations in gap size on forest microclimate and soil water content. The study site, in North West England, was a mixed temperate broadleaved deciduous forest dominated by mature sessile oak (Quercus petraea), beech (Fagus sylvatica) and ash (Fraxinus excelsior) with some representatives of sycamore (Acer pseudoplatanus). Solar radiation (I), air temperature (T(A)), soil temperature (T(S)), relative humidity (h), wind speed (v) and soil water content (Psi) were measured at four natural treefall gaps created after a severe storm in 2006 and adjacent sub-canopy sites. I, T(A), T(S), and Psi increased significantly with gap size; h was consistently lower in gaps than the sub-canopy but did not vary with gap size, while the variability of v could not be explained by the presence or size of gaps. There were systematic diurnal patterns in all microclimate variables in response to gaps, but no such patterns existed for Psi. These results further our understanding of the abiotic and consequent biotic responses to gaps in broadleaved deciduous forests created by natural treefalls, and provide a useful basis for evaluating the implications of forest management practices.

  6. Depth distribution and composition of seed banks under different tree layers in a managed temperate forest ecosystem

    NASA Astrophysics Data System (ADS)

    Godefroid, Sandrine; Phartyal, Shyam S.; Koedam, Nico

    2006-05-01

    In the present work we examined the composition and distribution across three soil layers of the buried soil seed bank under three different overstory types ( Fagus sylvatica, Quercus robur, Pinus sylvestris) and in logging areas in a 4383-ha forest in central Belgium. The objectives were: (1) to investigate whether species composition and species richness of soil seed banks are affected by different forest stands; (2) to examine how abundant are habitat-specific forest species in seed banks under different planted tree layers. The study was carried out in stands which are replicated, managed in the same way (even-aged high forest), and growing on the same soil type with the same land-use history. In the investigated area, the seed bank did show significant differences under oak, beech, pine and in logging areas, respectively in terms of size, composition and depth occurrence. All species and layers taken together, the seed bank size ranked as follows: oakwood > beechwood > logging area > pinewood. The same pattern was found for forest species. Seed numbers of Betula pendula, Calluna vulgaris, Dryopteris dilatata and Rubus fruticosus were significantly higher under the beech canopy. Carex remota, Impatiens parviflora and Lotus sp. showed a significantly denser seed bank in logging areas, while Digitalis purpurea seeds were significantly more abundant in soils under the oak canopy. The fact that the seed bank of an originally homogeneous forest varies under different planted stands highlights that a long period of canopy conversion can affect the composition and depth of buried seeds.

  7. In situ assessment of the velocity of carbon transfer by tracing 13 C in trunk CO2 efflux after pulse labelling: variations among tree species and seasons.

    PubMed

    Dannoura, Masako; Maillard, Pascale; Fresneau, Chantal; Plain, Caroline; Berveiller, Daniel; Gerant, Dominique; Chipeaux, Christophe; Bosc, Alexandre; Ngao, Jérôme; Damesin, Claire; Loustau, Denis; Epron, Daniel

    2011-04-01

    Phloem is the main pathway for transferring photosynthates belowground. In situ(13) C pulse labelling of trees 8-10 m tall was conducted in the field on 10 beech (Fagus sylvatica) trees, six sessile oak (Quercus petraea) trees and 10 maritime pine (Pinus pinaster) trees throughout the growing season. Respired (13) CO2 from trunks was tracked at different heights using tunable diode laser absorption spectrometry to determine time lags and the velocity of carbon transfer (V). The isotope composition of phloem extracts was measured on several occasions after labelling and used to estimate the rate constant of phloem sap outflux (kP ). Pulse labelling together with high-frequency measurement of the isotope composition of trunk CO2 efflux is a promising tool for studying phloem transport in the field. Seasonal variability in V was predicted in pine and oak by bivariate linear regressions with air temperature and soil water content. V differed among the three species consistently with known differences in phloem anatomy between broadleaf and coniferous trees. V increased with tree diameter in oak and beech, reflecting a nonlinear increase in volumetric flow with increasing bark cross-sectional area, which suggests changes in allocation pattern with tree diameter in broadleaf species. Discrepancies between V and kP indicate vertical changes in functional phloem properties.

  8. Impregnation of Scots pine and beech with tannin solutions: effect of viscosity and wood anatomy in wood infiltration.

    PubMed

    Tondi, G; Thevenon, M F; Mies, B; Standfest, G; Petutschnigg, A; Wieland, S

    The impregnation process of Scots pine and beech samples with tannin solutions was investigated. The two materials involved in the process (impregnation solution and wood samples) are studied in depth. Viscosity of mimosa tannin solutions and the anatomical aspect of beech and Scots pine were analysed and correlated. The viscosity of tannin solutions presents a non-newtonian behaviour when its pH level increases, and in the case of addition of hexamine as a hardener, the crosslinking of the flavonoids turns out to be of great importance. During the impregnation of Scots pine (Pinus sylvestris L.) and beech (Fagus sylvatica L.), the liquid and solid uptakes were monitored while taking into consideration the different conditions of the impregnation process. This method allowed to identify the best conditions needed in order to get a successful preservative uptake for each wooden substrate. The penetration mechanism within the wood of both species was revealed with the aid of a microscopic analysis. Scots pine is impregnated through the tracheids in the longitudinal direction and through parenchyma rays in the radial direction, whereas in beech, the penetration occurs almost completely through longitudinal vessels.

  9. Evidence for a Role of Gibberellins in Salicylic Acid-Modulated Early Plant Responses to Abiotic Stress in Arabidopsis Seeds1

    PubMed Central

    Alonso-Ramírez, Ana; Rodríguez, Dolores; Reyes, David; Jiménez, Jesús Angel; Nicolás, Gregorio; López-Climent, María; Gómez-Cadenas, Aurelio; Nicolás, Carlos

    2009-01-01

    Exogenous application of gibberellic acid (GA3) was able to reverse the inhibitory effect of salt, oxidative, and heat stresses in the germination and seedling establishment of Arabidopsis (Arabidopsis thaliana), this effect being accompanied by an increase in salicylic acid (SA) levels, a hormone that in recent years has been implicated in plant responses to abiotic stress. Furthermore, this treatment induced an increase in the expression levels of the isochorismate synthase1 and nonexpressor of PR1 genes, involved in SA biosynthesis and action, respectively. In addition, we proved that transgenic plants overexpressing a gibberellin (GA)-responsive gene from beechnut (Fagus sylvatica), coding for a member of the GA3 stimulated in Arabidopsis (GASA) family (FsGASA4), showed a reduced GA dependence for growth and improved responses to salt, oxidative, and heat stress at the level of seed germination and seedling establishment. In 35S:FsGASA4 seeds, the improved behavior under abiotic stress was accompanied by an increase in SA endogenous levels. All these data taken together suggest that this GA-responsive gene and exogenous addition of GAs are able to counteract the inhibitory effects of these adverse environmental conditions in seed germination and seedling growth through modulation of SA biosynthesis. Furthermore, this hypothesis is supported by the fact that sid2 mutants, impaired in SA biosynthesis, are more sensitive to salt stress than wild type and are not affected by exogenous application of GA3. PMID:19439570

  10. Pure stands of temperate forest tree species modify soil respiration and N turnover

    NASA Astrophysics Data System (ADS)

    Brüggemann, N.; Rosenkranz, P.; Papen, H.; Pilegaard, K.; Butterbach-Bahl, K.

    2005-04-01

    The effects of five different tree species common in the temperate zone, i.e. beech (Fagus sylvatica L.), pedunculate oak (Quercus robur L.), Norway spruce (Picea abies [L.] Karst), Japanese larch (Larix leptolepis [Sichold and Zucc.] Gordon) and mountain pine (Pinus mugo Turra), on soil respiration, gross N mineralization and gross nitrification rates were investigated. Soils were sampled in spring and summer 2002 at a forest trial in Western Jutland, Denmark, where pure stands of the five tree species of the same age were growing on the same soil. Soil respiration, gross rates of N mineralization and nitrification were significantly higher in the organic layers than in the Ah horizons for all tree species and both sampling dates. In summer (July), the highest rates of soil respiration, gross N mineralization and gross nitrification were found in the organic layer under spruce, followed by beech > larch > oak > pine. In spring (April), these rates were also higher under spruce compared to the other tree species, but were significantly lower than in summer. For the Ah horizons no clear seasonal trend was observed for any of the processes examined. A linear relationship between soil respiration and gross N mineralization (r2=0.77), gross N mineralization and gross nitrification rates (r2=0.72), and between soil respiration and gross nitrification (r2=0.81) was found. The results obtained underline the importance of considering the effect of forest type on soil C and N transformations.

  11. Modelling carbon fluxes of forest and grassland ecosystems in Western Europe using the CARAIB dynamic vegetation model: evaluation against eddy covariance data.

    NASA Astrophysics Data System (ADS)

    Henrot, Alexandra-Jane; François, Louis; Dury, Marie; Hambuckers, Alain; Jacquemin, Ingrid; Minet, Julien; Tychon, Bernard; Heinesch, Bernard; Horemans, Joanna; Deckmyn, Gaby

    2015-04-01

    Eddy covariance measurements are an essential resource to understand how ecosystem carbon fluxes react in response to climate change, and to help to evaluate and validate the performance of land surface and vegetation models at regional and global scale. In the framework of the MASC project (« Modelling and Assessing Surface Change impacts on Belgian and Western European climate »), vegetation dynamics and carbon fluxes of forest and grassland ecosystems simulated by the CARAIB dynamic vegetation model (Dury et al., iForest - Biogeosciences and Forestry, 4:82-99, 2011) are evaluated and validated by comparison of the model predictions with eddy covariance data. Here carbon fluxes (e.g. net ecosystem exchange (NEE), gross primary productivity (GPP), and ecosystem respiration (RECO)) and evapotranspiration (ET) simulated with the CARAIB model are compared with the fluxes measured at several eddy covariance flux tower sites in Belgium and Western Europe, chosen from the FLUXNET global network (http://fluxnet.ornl.gov/). CARAIB is forced either with surface atmospheric variables derived from the global CRU climatology, or with in situ meteorological data. Several tree (e.g. Pinus sylvestris, Fagus sylvatica, Picea abies) and grass species (e.g. Poaceae, Asteraceae) are simulated, depending on the species encountered on the studied sites. The aim of our work is to assess the model ability to reproduce the daily, seasonal and interannual variablility of carbon fluxes and the carbon dynamics of forest and grassland ecosystems in Belgium and Western Europe.

  12. Specific impacts of beech and Norway spruce on the structure and diversity of the rhizosphere and soil microbial communities

    PubMed Central

    Uroz, S.; Oger, P.; Tisserand, E.; Cébron, A.; Turpault, M.-P.; Buée, M.; De Boer, W.; Leveau, J. H. J.; Frey-Klett, P.

    2016-01-01

    The impacts of plant species on the microbial communities and physico-chemical characteristics of soil are well documented for many herbs, grasses and legumes but much less so for tree species. Here, we investigate by rRNA and ITS amplicon sequencing the diversity of microorganisms from the three domains of life (Archaea, Bacteria and Eukaryota:Fungi) in soil samples taken from the forest experimental site of Breuil-Chenue (France). We discovered significant differences in the abundance, composition and structure of the microbial communities associated with two phylogenetically distant tree species of the same age, deciduous European beech (Fagus sylvatica) and coniferous Norway spruce (Picea abies Karst), planted in the same soil. Our results suggest a significant effect of tree species on soil microbiota though in different ways for each of the three microbial groups. Fungal and archaeal community structures and compositions are mainly determined according to tree species, whereas bacterial communities differ to a great degree between rhizosphere and bulk soils, regardless of the tree species. These results were confirmed by quantitative PCR, which revealed significant enrichment of specific bacterial genera, such as Burkholderia and Collimonas, known for their ability to weather minerals within the tree root vicinity. PMID:27302652

  13. Seasonal variations in terpene emission factors of dominant species in four ecosystems in NE Spain

    NASA Astrophysics Data System (ADS)

    Llusia, Joan; Peñuelas, Josep; Guenther, Alex; Rapparini, Francesca

    2013-05-01

    We studied the daily patterns in the rates of foliar terpene emissions by four typical species from the Mediterranean region in two days of early spring and two days of summer in 4 localities of increasing biomass cover in Northern Spain. The species studied were Thymelaea tinctoria (in Monegros), Quercus coccifera (in Garraf), Quercus ilex (in Prades) and Fagus sylvatica (in Montseny). Of the total 43 VOCs detected, 23 were monoterpenes, 5 sesquiterpenes and 15 were not terpenes. Sesquiterpenes were the main terpenes emitted from T. tinctoria. Total VOC emission rates were on average about 15 times higher in summer than in early spring. The maximum rates of emission were recorded around midday. Emissions nearly stopped in the dark. No significant differences were found for nocturnal total terpene emission rates between places and seasons. The seasonal variations in the rate of terpene emissions and in their chemical composition can be explained mainly by dramatic changes in emission factors (emission capacity) associated in some cases, such as for beech trees, with very different foliar ontogenical characteristics between spring and summer. The results show that temperature and light-standardised emission rates were on average about 15 times higher in summer than in early spring, which, corroborating other works, calls to attention when applying the same emission factor in modelling throughout the different seasons of the year.

  14. Network Analysis Reveals Ecological Links between N-Fixing Bacteria and Wood-Decaying Fungi

    PubMed Central

    Hoppe, Björn; Kahl, Tiemo; Karasch, Peter; Wubet, Tesfaye; Bauhus, Jürgen; Buscot, François; Krüger, Dirk

    2014-01-01

    Nitrogen availability in dead wood is highly restricted and associations with N-fixing bacteria are thought to enable wood-decaying fungi to meet their nitrogen requirements for vegetative and generative growth. We assessed the diversity of nifH (dinitrogenase reductase) genes in dead wood of the common temperate tree species Fagus sylvatica and Picea abies from differently managed forest plots in Germany using molecular tools. By incorporating these genes into a large compilation of published nifH sequences and subsequent phylogenetic analyses of deduced proteins we verified the presence of diverse pools corresponding to functional nifH, almost all of which are new to science. The distribution of nifH genes strongly correlated with tree species and decay class, but not with forest management, while higher fungal fructification was correlated with decreasing nitrogen content of the dead wood and positively correlated with nifH diversity, especially during the intermediate stage of wood decay. Network analyses based on non-random species co-occurrence patterns revealed interactions among fungi and N-fixing bacteria in the dead wood and strongly indicate the occurrence of at least commensal relationships between these taxa. PMID:24505405

  15. A mathematical model linking tree sap flow dynamics to daily stem diameter fluctuations and radial stem growth.

    PubMed

    Steppe, Kathy; De Pauw, Dirk J W; Lemeur, Raoul; Vanrolleghem, Peter A

    2006-03-01

    To date, models for simulating sap flow dynamics in individual trees with a direct link to stem diameter variation include only the diameter fluctuation driven by a change in stem water storage. This paper reports results obtained with a comprehensive flow and storage model using whole-tree leaf transpiration as the only input variable. The model includes radial stem growth based on Lockhart's equation for irreversible cell expansion. It was demonstrated that including growth is essential to obtaining good simulation results. To model sap flow dynamics, capacitance of storage tissues was assumed either constant (i.e., electrical analogue approach) or variable and dependent on the water content of the respective storage tissue (i.e., hydraulic system approach). These approaches resulted in different shapes for the desorption curve used to calculate the capacitance of storage tissues. Comparison of these methods allowed detection of specific differences in model simulation of sap flow at the stem base (F(stem)) and stem diameter variation (D). Sensitivity analysis was performed to select a limited subset of identifiable parameters driving most of the variability in model predictions of F(stem) and D Both the electrical analogue and the hydraulic system approach for the flow and storage model were successfully calibrated and validated for the case of a young beech tree (Fagus sylvatica L.). Use of an objective model selection criterion revealed that the flow and storage model based on the electrical analogue approach yielded better predictions.

  16. Contrasting effects of elevated temperature and invertebrate grazing regulate multispecies interactions between decomposer fungi.

    PubMed

    A'Bear, A Donald; Murray, William; Webb, Rachel; Boddy, Lynne; Jones, T Hefin

    2013-01-01

    Predicting the influence of biotic and abiotic factors on species interactions and ecosystem processes is among the primary aims of community ecologists. The composition of saprotrophic fungal communities is a consequence of competitive mycelial interactions, and a major determinant of woodland decomposition and nutrient cycling rates. Elevation of atmospheric temperature is predicted to drive changes in fungal community development. Top-down regulation of mycelial growth is an important determinant of, and moderator of temperature-driven changes to, two-species interaction outcomes. This study explores the interactive effects of a 4 °C temperature increase and soil invertebrate (collembola or woodlice) grazing on multispecies interactions between cord-forming basidiomycete fungi emerging from colonised beech (Fagus sylvatica) wood blocks. The fungal dominance hierarchy at ambient temperature (16 °C; Phanerochaete velutina > Resinicium bicolor > Hypholoma fasciculare) was altered by elevated temperature (20 °C; R. bicolor > P. velutina > H. fasciculare) in ungrazed systems. Warming promoted the competitive ability of the fungal species (R. bicolor) that was preferentially grazed by all invertebrate species. As a consequence, grazing prevented the effect of temperature on fungal community development and maintained a multispecies assemblage. Decomposition of fungal-colonised wood was stimulated by warming, with implications for increased CO2 efflux from woodland soil. Analogous to aboveground plant communities, increasing complexity of biotic and abiotic interactions appears to be important in buffering climate change effects on soil decomposers.

  17. Resurrection kinetics of photosynthesis in desiccation-tolerant terrestrial green algae (Chlorophyta) on tree bark.

    PubMed

    Lüttge, U; Büdel, B

    2010-05-01

    The rough bark of orchard trees (Malus) around Darmstadt is predominantly covered in red to purple-brown layers (biofilms) of epiphytic terrestrial alga of Trentepohlia umbrina. The smooth bark of forest trees (Fagus sylvatica L. and Acer sp.) in the same area is covered by bright green biofilms composed of the green algae Desmococcus, Apatococcus and Trebouxia, with a few cells of Coccomyxa and 'Chlorella' trebouxioides between them. These algae are desiccation tolerant. After samples of bark with the biofilms were kept in dry air in darkness for various periods of time, potential quantum yield of PSII, F(v)/F(m), recovered during rehydration upon rewetting. The kinetics and degree of recovery depended on the length of time that the algae were kept in dry air in the desiccated state. Recovery was better for green biofilm samples, i.e. quite good even after 80 days of desiccation (F(v)/F(m) = ca. 50% of initial value), than the red samples, where recovery was only adequate up to ca. 30-40 days of desiccation (F(v)/F(m) = ca. 20-55% of initial value). It is concluded that the different bark types constitute different ecophysiological niches that can be occupied by the algae and that can be distinguished by their capacity to recover from desiccation after different times in the dry state.

  18. Sapflow+: a four-needle heat-pulse sap flow sensor enabling nonempirical sap flux density and water content measurements.

    PubMed

    Vandegehuchte, Maurits W; Steppe, Kathy

    2012-10-01

    • To our knowledge, to date, no nonempirical method exists to measure reverse, low or high sap flux density. Moreover, existing sap flow methods require destructive wood core measurements to determine sapwood water content, necessary to convert heat velocity to sap flux density, not only damaging the tree, but also neglecting seasonal variability in sapwood water content. • Here, we present a nonempirical heat-pulse-based method and coupled sensor which measure temperature changes around a linear heater in both axial and tangential directions after application of a heat pulse. By fitting the correct heat conduction-convection equation to the measured temperature profiles, the heat velocity and water content of the sapwood can be determined. • An identifiability analysis and validation tests on artificial and real stem segments of European beech (Fagus sylvatica L.) confirm the applicability of the method, leading to accurate determinations of heat velocity, water content and hence sap flux density. • The proposed method enables sap flux density measurements to be made across the entire natural occurring sap flux density range of woody plants. Moreover, the water content during low flows can be determined accurately, enabling a correct conversion from heat velocity to sap flux density without destructive core measurements.

  19. Effects of drought on mesophyll conductance and photosynthetic limitations at different tree canopy layers.

    PubMed

    Cano, F Javier; Sánchez-Gómez, David; Rodríguez-Calcerrada, Jesús; Warren, Charles R; Gil, Luis; Aranda, Ismael

    2013-11-01

    In recent years, many studies have focused on the limiting role of mesophyll conductance (gm ) to photosynthesis (An ) under water stress, but no studies have examined the effect of drought on gm through the forest canopy. We investigated limitations to An on leaves at different heights in a mixed adult stand of sessile oak (Quercus petraea) and beech (Fagus sylvatica) trees during a moderately dry summer. Moderate drought decreased An of top and lowest beech canopy leaves much more than in leaves located in the mid canopy; whereas in oak, An of the lower canopy was decreased more than in sunlit leaves. The decrease of An was probably not due to leaf-level biochemistry given that VCmax was generally unaffected by drought. The reduction in An was instead associated with reduction in stomatal and mesophyll conductances. Drought-induced increases in stomatal limitations were largest in leaves from the top canopy, whereas drought-induced increases in mesophyll limitations were largest in leaves from the lowest canopy. Sensitivity analysis highlighted the need to decompose the canopy into different leaf layers and to incorporate the limitation imposed by gm when assessing the impact of drought on the gas exchange of tree canopies.

  20. Impact of the 2013-2015 weather variability on seasonal growth dynamics and daily stem-size changes of three coexisting broadleaved tree species

    NASA Astrophysics Data System (ADS)

    van der Maaten, Ernst; Pape, Jonas; van der Maaten Theunissen, Marieke; Scharnweber, Tobias; Smiljanic, Marko; Wilmking, Martin

    2016-04-01

    Dendrometers are measurement devices that continuously monitor stem-size changes of trees without invasive sampling of the cambium. Dendrometers record both irreversible tree growth as well as reversible signals of stem water storage and depletion, making them important tools for studying tree water status, tree physiology and short-term growth responses of trees to weather fluctuations. In this study, a three-year dendrometer dataset (2013-2015) is used to study seasonal growth dynamics and daily stem-size changes of three coexisting broadleaved tree species (common hornbeam (Carpinus betulus L.), European beech (Fagus sylvatica L.), and pedunculate oak (Quercus robur L.)), growing in an unmanaged forest in northeastern Germany. Seasonal growth patterns (i.e. growth onset, cessation and duration) are analyzed in relation to environmental conditions, and forest meteorological factors driving daily stem-size changes are identified. Following dry conditions in 2014, especially the growth of beech was reduced. Oak was less affected, and displayed a distinct early growth onset for all study years.

  1. Assessing the risk caused by ground level ozone to European forest trees: a case study in pine, beech and oak across different climate regions.

    PubMed

    Emberson, Lisa D; Büker, Patrick; Ashmore, Mike R

    2007-06-01

    Two different indices have been proposed for estimation of the risk caused to forest trees across Europe by ground-level ozone, (i) the concentration based AOT40 index (Accumulated Over a Threshold of 40 ppb) and (ii) the recently developed flux based AFstY index (Accumulated stomatal Flux above a flux threshold Y). This paper compares the AOT40 and AFstY indices for three forest trees species at different locations in Europe. The AFstY index is estimated using the DO(3)SE (Deposition of Ozone and Stomatal Exchange) model parameterized for Scots pine (Pinus sylvestris), beech (Fagus sylvatica) and holm oak (Quercus ilex). The results show a large difference in the perceived O(3) risk when using AOT40 and AFstY indices both between species and regions. The AOT40 index shows a strong north-south gradient across Europe, whereas there is little difference between regions in the modelled values of AFstY. There are significant differences in modelled AFstY between species, which are predominantly determined by differences in the timing and length of the growing season, the periods during which soil moisture deficit limits stomatal conductance, and adaptation to soil moisture stress. This emphasizes the importance of defining species-specific flux response variables to obtain a more accurate quantification of O(3) risk.

  2. Seasonal changes of C and N non-structural compounds in the stem sapwood of adult sessile oak and beech trees.

    PubMed

    El Zein, R; Maillard, P; Bréda, N; Marchand, J; Montpied, P; Gérant, D

    2011-08-01

    We assessed the pools of non-structural nitrogen compounds (NSNC) through a year, thereby addressing the question of whether mature sessile oak [Quercus petraea (Matt.) Liebl.] and beech (Fagus sylvatica L.), which differ in wood anatomy and growth patterns, exhibit contrasting seasonal dynamics of NSNC pools as previously shown for non-structural carbohydrate (NSC) pools. Seasonal fluctuations of NSNC (amino acids and soluble proteins) and NSC (starch and soluble sugars) pools were analyzed in the inner and the outer stem sapwood. In oak, NSC showed marked seasonal variation within the stem sapwood (accumulation during winter and decrease during bud burst and early wood growth), whereas in beech seasonal fluctuations in NSC were of minor amplitude. Even if the distribution and intensity of the NSNC pools differed between the two species, NSNC of the stem sapwood did not show seasonal variation. The most significant change in NSNC pools was the seasonal fluctuation of protein composition. In both species, two polypeptides of 13 kDa (PP13) and 26 kDa (PP26) accumulated during the coldest period in parallel with starch to sugar conversion and disappeared with the onset of spring growth. The absence of seasonal changes in total soluble protein concentration suggests that the polypeptides are involved in the internal nitrogen (N) cycling of the stem rather than in N storage and remobilization to the other growing organs of the tree.

  3. Advantages of masting in European beech: timing of granivore satiation and benefits of seed caching support the predator dispersal hypothesis.

    PubMed

    Zwolak, Rafał; Bogdziewicz, Michał; Wróbel, Aleksandra; Crone, Elizabeth E

    2016-03-01

    The predator satiation and predator dispersal hypotheses provide alternative explanations for masting. Both assume satiation of seed-eating vertebrates. They differ in whether satiation occurs before or after seed removal and caching by granivores (predator satiation and predator dispersal, respectively). This difference is largely unrecognized, but it is demographically important because cached seeds are dispersed and often have a microsite advantage over nondispersed seeds. We conducted rodent exclosure experiments in two mast and two nonmast years to test predictions of the predator dispersal hypothesis in our study system of yellow-necked mice (Apodemus flavicollis) and European beech (Fagus sylvatica). Specifically, we tested whether the fraction of seeds removed from the forest floor is similar during mast and nonmast years (i.e., lack of satiation before seed caching), whether masting decreases the removal of cached seeds (i.e., satiation after seed storage), and whether seed caching increases the probability of seedling emergence. We found that masting did not result in satiation at the seed removal stage. However, masting decreased the removal of cached seeds, and seed caching dramatically increased the probability of seedling emergence relative to noncached seeds. European beech thus benefits from masting through the satiation of scatterhoarders that occurs only after seeds are removed and cached. Although these findings do not exclude other evolutionary advantages of beech masting, they indicate that fitness benefits of masting extend beyond the most commonly considered advantages of predator satiation and increased pollination efficiency.

  4. Status of the Southern Carpathian forests in the long-term ecological research network.

    PubMed

    Badea, Ovidiu; Bytnerowicz, Andrzej; Silaghi, Diana; Neagu, Stefan; Barbu, Ion; Iacoban, Carmen; Iacob, Corneliu; Guiman, Gheorghe; Preda, Elena; Seceleanu, Ioan; Oneata, Marian; Dumitru, Ion; Huber, Viorela; Iuncu, Horia; Dinca, Lucian; Leca, Stefan; Taut, Ioan

    2012-12-01

    Air pollution, bulk precipitation, throughfall, soil condition, foliar nutrients, as well as forest health and growth were studied in 2006-2009 in a long-term ecological research (LTER) network in the Bucegi Mountains, Romania. Ozone (O(3)) was high indicating a potential for phytotoxicity. Ammonia (NH(3)) concentrations rose to levels that could contribute to deposition of nutritional nitrogen (N) and could affect biodiversity changes. Higher that 50% contribution of acidic rain (pH < 5.5) contributed to increased acidity of forest soils. Foliar N concentrations for Norway spruce (Picea abies), Silver fir (Abies alba), Scots pine (Pinus sylvestris), and European beech (Fagus sylvatica) were normal, phosphorus (P) was high, while those of potassium (K), magnesium (Mg), and especially of manganese (Mn) were significantly below the typical European or Carpathian region levels. The observed nutritional imbalance could have negative effects on forest trees. Health of forests was moderately affected, with damaged trees (crown defoliation >25%) higher than 30%. The observed crown damage was accompanied by the annual volume losses for the entire research forest area up to 25.4%. High diversity and evenness specific to the stand type's structures and local climate conditions were observed within the herbaceous layer, indicating that biodiversity of the vascular plant communities was not compromised.

  5. Network analysis reveals ecological links between N-fixing bacteria and wood-decaying fungi.

    PubMed

    Hoppe, Björn; Kahl, Tiemo; Karasch, Peter; Wubet, Tesfaye; Bauhus, Jürgen; Buscot, François; Krüger, Dirk

    2014-01-01

    Nitrogen availability in dead wood is highly restricted and associations with N-fixing bacteria are thought to enable wood-decaying fungi to meet their nitrogen requirements for vegetative and generative growth. We assessed the diversity of nifH (dinitrogenase reductase) genes in dead wood of the common temperate tree species Fagus sylvatica and Picea abies from differently managed forest plots in Germany using molecular tools. By incorporating these genes into a large compilation of published nifH sequences and subsequent phylogenetic analyses of deduced proteins we verified the presence of diverse pools corresponding to functional nifH, almost all of which are new to science. The distribution of nifH genes strongly correlated with tree species and decay class, but not with forest management, while higher fungal fructification was correlated with decreasing nitrogen content of the dead wood and positively correlated with nifH diversity, especially during the intermediate stage of wood decay. Network analyses based on non-random species co-occurrence patterns revealed interactions among fungi and N-fixing bacteria in the dead wood and strongly indicate the occurrence of at least commensal relationships between these taxa.

  6. Physical and chemical properties of some imported woods and their degradation by termites.

    PubMed

    Shanbhag, Rashmi R; Sundararaj, R

    2013-01-01

    The influence of physical and chemical properties of 20 species of imported wood on degradation of the wood by termites under field conditions was studied. The wood species studied were: Sycamore maple, Acer pseudoplatanus L. (Sapindales: Sapindaceae) (from two countries), Camphor, Dryobalanops aromatic C.F.Gaertner (Malvales: Dipterocarpaceae), Beech, Fagus grandifolia Ehrhart (Fagales: Fagaceae), F. sylvatica L. (from two countries), Oak, Quercus robur L., Ash, Fraxinus angustifolia Vahl (Lamiales: Oleaceae), F. excelsior L., Padauk, Pterocarpus soyauxii Taubert (Fabales: Fabaceae), (from two countries), Jamba, Xylia dolabrifiormis Roxburgh, Shorea laevis Ridley (Malvales: Dipterocarpaceae), S. macoptera Dyer, S. robusta Roth, Teak, Tectona grandis L.f. (Lamiales: Lamiaceae) (from five countries), and rubber tree, Hevea brasiliensis Müller Argoviensis (Malpighiales: Euphorbiaceae) from India. The termites present were: Odontotermes horni (Wasmann) (Isoptera: Termitidae), O. feae, O. wallonensis, and O. obeus (Rambur). A significant conelation was found between density, cellulose, lignin, and total phenolic contents of the wood and degradation by termites. The higher the density of the wood, the lower the degradation. Similarly, higher amount of lignin and total phenolic contents ensured higher resistance, whereas cellulose drives the termites towards the wood.

  7. Evidence for a role of gibberellins in salicylic acid-modulated early plant responses to abiotic stress in Arabidopsis seeds.

    PubMed

    Alonso-Ramírez, Ana; Rodríguez, Dolores; Reyes, David; Jiménez, Jesús Angel; Nicolás, Gregorio; López-Climent, María; Gómez-Cadenas, Aurelio; Nicolás, Carlos

    2009-07-01

    Exogenous application of gibberellic acid (GA(3)) was able to reverse the inhibitory effect of salt, oxidative, and heat stresses in the germination and seedling establishment of Arabidopsis (Arabidopsis thaliana), this effect being accompanied by an increase in salicylic acid (SA) levels, a hormone that in recent years has been implicated in plant responses to abiotic stress. Furthermore, this treatment induced an increase in the expression levels of the isochorismate synthase1 and nonexpressor of PR1 genes, involved in SA biosynthesis and action, respectively. In addition, we proved that transgenic plants overexpressing a gibberellin (GA)-responsive gene from beechnut (Fagus sylvatica), coding for a member of the GA(3) stimulated in Arabidopsis (GASA) family (FsGASA4), showed a reduced GA dependence for growth and improved responses to salt, oxidative, and heat stress at the level of seed germination and seedling establishment. In 35S:FsGASA4 seeds, the improved behavior under abiotic stress was accompanied by an increase in SA endogenous levels. All these data taken together suggest that this GA-responsive gene and exogenous addition of GAs are able to counteract the inhibitory effects of these adverse environmental conditions in seed germination and seedling growth through modulation of SA biosynthesis. Furthermore, this hypothesis is supported by the fact that sid2 mutants, impaired in SA biosynthesis, are more sensitive to salt stress than wild type and are not affected by exogenous application of GA(3).

  8. Effects of drought on leaf carbon source and growth of European beech are modulated by soil type

    PubMed Central

    Liu, Jian-Feng; Arend, Matthias; Yang, Wen-Juan; Schaub, Marcus; Ni, Yan-Yan; Gessler, Arthur; Jiang, Ze-Ping; Rigling, Andreas; Li, Mai-He

    2017-01-01

    Drought potentially affects carbon balance and growth of trees, but little is known to what extent soil plays a role in the trade-off between carbon gain and growth investment. In the present study, we analyzed leaf non-structural carbohydrates (NSC) as an indicator of the balance of photosynthetic carbon gain and carbon use, as well as growth of European beech (Fagus sylvatica L.) saplings, which were grown on two different soil types (calcareous and acidic) in model ecosystems and subjected to a severe summer drought. Our results showed that drought led in general to increased total NSC concentrations and to decreased growth rate, and drought reduced shoot and stem growth of plants in acidic soil rather than in calcareous soil. This result indicated that soil type modulated the carbon trade-off between net leaf carbon gain and carbon investment to growth. In drought-stressed trees, leaf starch concentration and growth correlated negatively whereas soluble sugar:starch ratio and growth correlated positively, which may contribute to a better understanding of growth regulation under drought conditions. Our results emphasize the role of soil in determining the trade-off between the balance of carbon gain and carbon use on the leaf level and growth under stress (e.g. drought). PMID:28195166

  9. Tree Species Classification By Multiseasonal High Resolution Satellite Data

    NASA Astrophysics Data System (ADS)

    Elatawneh, Alata; Wallner, Adelheid; Straub, Christoph; Schneider, Thomas; Knoke, Thomas

    2013-12-01

    Accurate forest tree species mapping is a fundamental issue for sustainable forest management and planning. Forest tree species mapping with the means of remote sensing data is still a topic to be investigated. The Bavaria state institute of forestry is investigating the potential of using digital aerial images for forest management purposes. However, using aerial images is still cost- and time-consuming, in addition to their acquisition restrictions. The new space-born sensor generations such as, RapidEye, with a very high temporal resolution, offering multiseasonal data have the potential to improve the forest tree species mapping. In this study, we investigated the potential of multiseasonal RapidEye data for mapping tree species in a Mid European forest in Southern Germany. The RapidEye data of level A3 were collected on ten different dates in the years 2009, 2010 and 2011. For data analysis, a model was developed, which combines the Spectral Angle Mapper technique with a 10-fold- cross-validation. The analysis succeeded to differentiate four tree species; Norway spruce (Picea abies L.), Silver Fir (Abies alba Mill.), European beech (Fagus sylvatica) and Maple (Acer pseudoplatanus). The model success was evaluated using digital aerial images acquired in the year 2009 and inventory point records from 2008/09 inventory. Model results of the multiseasonal RapidEye data analysis achieved an overall accuracy of 76%. However, the success of the model was evaluated only for all the identified species and not for the individual.

  10. Types of ectomycorrhiza as pollution stress indicators: case studies in Slovenia.

    PubMed

    Kraigher, Hojka; Al Sayegh Petkovsek, Samar; Grebenc, Tine; Simoncic, Primoz

    2007-05-01

    Mycorrhiza is the main spatial and temporal linkage between different constituents in a forest ecosystem. The functional compatibility and stress tolerance of ectomycorrhizal types is species specific, and therefore the information on the ectomycorrhizal community structure can add to the understanding of processes in forest ecosystems and can also be applied as tools for bioindication of pollution stress in forest soils. We have studied the effects of pollution (N and S) on trees and forest soils by: (1) quantification of ECM types diversity as in situ indicators in forest stands, (2) determination and quantification of pollution-sensitive or -insensitive ECM types as passive monitors, (3) root growth and development of ECM on nonmycorrhizal spruce seedlings, planted at the studied sites (active monitors), and (4) ECM infection (a bioassay based on mycorrhizal inoculum potential) of seedlings in an experimental set-up as ex situ testers. ECM species richness for Norway spruce trees (Picea abies) showed higher values in unpolluted sites than in polluted ones, while the differences were not significant for European beech trees (Fagus sylvatica). As pollution-sensitive or -insensitive ECM species in spruce forests, we suggest Hydnum rufescens (sensitive) and Paxillus involutus (unsensitive). Mycorrhizal potential in Norway spruce seedlings as a bioassay for soil N and S pollution was effective, and is suggested as an additional, standardized and widely comparable system in bioindication of soil pollution.

  11. Limited transfer of nitrogen between wood decomposing and ectomycorrhizal mycelia when studied in the field.

    PubMed

    Wallander, Håkan; Lindahl, Björn D; Nilsson, Lars Ola

    2006-05-01

    Transfer of (15)N between interacting mycelia of a wood-decomposing fungus (Hypholoma fasciculare) and an ectomycorrhizal fungus (Tomentellopsis submollis) was studied in a mature beech (Fagus sylvatica) forest. The amount of (15)N transferred from the wood decomposer to the ectomycorrhizal fungus was compared to the amount of (15)N released from the wood-decomposing mycelia into the soil solution as (15)N-NH(4). The study was performed in peat-filled plastic containers placed in forest soil in the field. The wood-decomposing mycelium was growing from an inoculated wood piece and the ectomycorrhizal mycelium from an introduced root from a mature tree. The containers were harvested after 41 weeks when physical contact between the two foraging mycelia was established. At harvest, (15)N content was analyzed in the peat (total N and (15)NH(4) (+)) and in the mycorrhizal roots. A limited amount of (15)N was transferred to the ectomycorrhizal fungus and this transfer could be explained by (15)NH(4) (+) released from the wood-decomposing fungus without involving any antagonistic interactions between the two mycelia. Using our approach, it was possible to study nutritional interactions between basidiomycete mycelia under field conditions and this and earlier studies suggest that the outcomes of such interactions are highly species-specific and depend on environmental conditions such as resource availability.

  12. Simulating local adaptation to climate of forest trees with a Physio-Demo-Genetics model

    PubMed Central

    Oddou-Muratorio, Sylvie; Davi, Hendrik

    2014-01-01

    One challenge of evolutionary ecology is to predict the rate and mechanisms of population adaptation to environmental variations. The variations in most life history traits are shaped both by individual genotypic and by environmental variation. Forest trees exhibit high levels of genetic diversity, large population sizes, and gene flow, and they also show a high level of plasticity for life history traits. We developed a new Physio-Demo-Genetics model (denoted PDG) coupling (i) a physiological module simulating individual tree responses to the environment; (ii) a demographic module simulating tree survival, reproduction, and pollen and seed dispersal; and (iii) a quantitative genetics module controlling the heritability of key life history traits. We used this model to investigate the plastic and genetic components of the variations in the timing of budburst (TBB) along an elevational gradient of Fagus sylvatica (the European beech). We used a repeated 5 years climatic sequence to show that five generations of natural selection were sufficient to develop nonmonotonic genetic differentiation in the TBB along the local climatic gradient but also that plastic variation among different elevations and years was higher than genetic variation. PDG complements theoretical models and provides testable predictions to understand the adaptive potential of tree populations. PMID:24822080

  13. Introduction to Distribution and Ecology of Sterile Conks of Inonotus obliquus

    PubMed Central

    Hur, Hyeon; Chang, Kwang-Choon; Lee, Tae-Soo; Ka, Kang-Hyeon; Jankovsky, L.

    2008-01-01

    Inonotus obliquus is a fungus that causes white heart rot on several broad-leaved species. This fungus forms typical charcoal-black, sterile conks (chaga) or cinder conks on infected stems of the birche (Betula spp). The dark brown pulp of the sterile conk is formed by a pure mycelial mass of fungus. Chaga are a folk remedy in Russia, reflecting the circumboreal distribution of I. obliquus in boreal forest ecosystems on Betula spp. and in meridional mountain forests on beech (Fagus spp.) in Russia, Scandinavia, Central Europe, and Eastern Europe. Distribution at lower latitudes in Western and Southern Europe, Northern America, Asia, Japan, and Korea is rare. Infected trees grow for many years without several symptoms of decline. The infection can penetrate through stem injuries with exterior sterile conks developing later. In the Czech Republic, cinder conk is found on birches inhabiting peat bogs and in mountain areas with a colder and more humid climate, although it is widespread in other broad leaved species over the Czech Republic. The most common hosts are B. pendula, B. pubescens, B. carpatica, and F. sylvatica. Less frequent hosts include Acer campestre, Acer pseudoplatanus, Alnus glutinosa, Alnus incana, Fraxinus excelsior, Quercus cerris, Q. petraea, Q. robur, Q. delachampii, and Ulmus sp. PMID:23997626

  14. Effects of drought on leaf carbon source and growth of European beech are modulated by soil type

    NASA Astrophysics Data System (ADS)

    Liu, Jian-Feng; Arend, Matthias; Yang, Wen-Juan; Schaub, Marcus; Ni, Yan-Yan; Gessler, Arthur; Jiang, Ze-Ping; Rigling, Andreas; Li, Mai-He

    2017-02-01

    Drought potentially affects carbon balance and growth of trees, but little is known to what extent soil plays a role in the trade-off between carbon gain and growth investment. In the present study, we analyzed leaf non-structural carbohydrates (NSC) as an indicator of the balance of photosynthetic carbon gain and carbon use, as well as growth of European beech (Fagus sylvatica L.) saplings, which were grown on two different soil types (calcareous and acidic) in model ecosystems and subjected to a severe summer drought. Our results showed that drought led in general to increased total NSC concentrations and to decreased growth rate, and drought reduced shoot and stem growth of plants in acidic soil rather than in calcareous soil. This result indicated that soil type modulated the carbon trade-off between net leaf carbon gain and carbon investment to growth. In drought-stressed trees, leaf starch concentration and growth correlated negatively whereas soluble sugar:starch ratio and growth correlated positively, which may contribute to a better understanding of growth regulation under drought conditions. Our results emphasize the role of soil in determining the trade-off between the balance of carbon gain and carbon use on the leaf level and growth under stress (e.g. drought).

  15. Variation in leaf flushing date influences autumnal senescence and next year's flushing date in two temperate tree species.

    PubMed

    Fu, Yongshuo S H; Campioli, Matteo; Vitasse, Yann; De Boeck, Hans J; Van den Berge, Joke; AbdElgawad, Hamada; Asard, Han; Piao, Shilong; Deckmyn, Gaby; Janssens, Ivan A

    2014-05-20

    Recent temperature increases have elicited strong phenological shifts in temperate tree species, with subsequent effects on photosynthesis. Here, we assess the impact of advanced leaf flushing in a winter warming experiment on the current year's senescence and next year's leaf flushing dates in two common tree species: Quercus robur L. and Fagus sylvatica L. Results suggest that earlier leaf flushing translated into earlier senescence, thereby partially offsetting the lengthening of the growing season. Moreover, saplings that were warmed in winter-spring 2009-2010 still exhibited earlier leaf flushing in 2011, even though the saplings had been exposed to similar ambient conditions for almost 1 y. Interestingly, for both species similar trends were found in mature trees using a long-term series of phenological records gathered from various locations in Europe. We hypothesize that this long-term legacy effect is related to an advancement of the endormancy phase (chilling phase) in response to the earlier autumnal senescence. Given the importance of phenology in plant and ecosystem functioning, and the prediction of more frequent extremely warm winters, our observations and postulated underlying mechanisms should be tested in other species.

  16. Application of micro-PIXE, MRI and light microscopy for research in wood science and dendroecology

    NASA Astrophysics Data System (ADS)

    Merela, M.; Pelicon, P.; Vavpetič, P.; Regvar, M.; Vogel-Mikuš, K.; Serša, I.; Poličnik, H.; Pokorny, B.; Levanič, T.; Oven, P.

    2009-06-01

    Beech ( Fagus sylvatica L.) branches were topped and after five months the wound response was analyzed by PIXE, 3D-MRI and light microscopy. From freshly cut and deeply frozen sample 30 μm thick longitudinal-radial tissue sections were prepared for anatomical investigations and micro-PIXE analysis. Light microscopy revealed the structural response to wounding, i.e. occurrence of the reaction zone between the exposed and dehydrated dead tissue and healthy sound wood. The reaction zone was characterized by tylosis in vessels and accumulation of colored deposits in parenchyma cells, fibres and vessels. 3D MRI of a parallel sample showed that the moisture content in the reaction zone was three times higher than in normal healthy wood. Micro-PIXE mapping at margins of compromised wood in beech revealed an increased concentration of potassium in the reaction zone. The increase in the calcium concentration was associated with the dehydrated tissue adjacent to reaction zones. In addition, micro-PIXE was used to determine the elemental distribution in annual tree rings. This may be relevant for retrospective assessment of environmental pollution in wood by measuring yearly increments as a biomonitoring tool. The analysis of European larch ( Larix decidua Mill.) wood revealed a high similarity between optical characteristics (i.e. late versus earlywood) and elemental (e.g. Cl, K, Ca, Mn, Zn) distribution.

  17. Negative effects of density on space use of small mammals differ with the phase of the masting-induced population cycle.

    PubMed

    Bogdziewicz, Michał; Zwolak, Rafał; Redosh, Lauren; Rychlik, Leszek; Crone, Elizabeth E

    2016-12-01

    Home range size generally decreases with increasing population density, but testing how this relationship is influenced by other factors (e.g., food availability, kin structure) is a difficult task. We used spatially explicit capture-recapture models to examine how home range size varies with population density in the yellow-necked mouse (Apodemus flavicollis). The relationship between population density and home range size was studied at two distinct phases of population fluctuations induced by beech (Fagus sylvatica) masting: post-mast peak in abundance (first summer after mast, n = 2) and subsequent crash (second summer after mast, n = 2). We live-trapped mice from June to September to avoid the confounding effects of autumn seedfall on home range size. In accordance with general predictions, we found that home range size was negatively associated with population density. However, after controlling for the effect of density, home ranges of mice were larger in post-mast years than during the crash phase. This indicates a higher spatial overlap among neighbors in post-mast years. We suggest that the increased spatial overlap is caused by negative density-dependent dispersal that leads to high relatedness of individuals within population in the peak phase of the cycle.

  18. Is energy supply the trigger for reproductive activity in male edible dormice (Glis glis)?

    PubMed

    Fietz, Joanna; Kager, Timo; Schauer, Sebastian

    2009-10-01

    In edible dormice (Glis glis) reproduction is synchronised with the intermittent masting of the European beech (Fagus sylvatica). In years of mast failure dormouse males seem to anticipate future low food availability and fail to develop functional testes. We hypothesised that the availability of high-quality food is linked to male reproductive capacity, because of high male energetic demands during gonad maturation. We therefore evaluated the relationship between beech seed production and male reproductivity in the field between 1993 and 2005. In order to know whether the energy content of the food as such triggers sexual capacity, we supplemented high-quality food in the field for 3 years and investigated reproductive output, reproductive capacity, and body mass changes. Results revealed that male reproductive capacity was positively linked with beech seed production. Body mass changes of reference males during the high reproductive year further revealed high energetic demands of male reproduction, which were counter balanced in food-supplemented males. However, in contrast to our assumptions, artificial food supply during a year of mast failure failed to evoke high reproductivity in edible dormice. The availability of high-quality food can therefore be ruled out from being the primary trigger for sexual activity in male edible dormice.

  19. Observations of the uptake of carbonyl sulfide (COS) by trees under elevated atmospheric carbon dioxide concentrations

    NASA Astrophysics Data System (ADS)

    Sandoval-Soto, L.; Kesselmeier, M.; Schmitt, V.; Wild, A.; Kesselmeier, J.

    2012-02-01

    Global change affects ecosystems to adapt to elevated atmospheric concentrations of carbon dioxide (CO2). We understand that carbonyl sulfide (COS), a trace gas which is involved in building up the stratospheric sulfate aerosol layer, is taken up by vegetation with the same triad of the enzmyes which are metabolizing the CO2, i.e. Ribulose-1,5-bisphosphate Carboxylase-Oxygenase (Rubisco), Phosphoenolpyruvate Carboxylase (PEP-Co) and carbonic anhydrase (CA). Therefore, we discuss a physiological/biochemical adaptation of these enzymes to affect the sink strength of vegetation for COS. We investigated the adaption of two European tree species, Fagus sylvatica and Quercus ilex, grown inside chambers under elevated CO2 and determined the exchange characteristics and the content of CA after a 1-2 yr period of adaption from 350 ppm to 800 ppm CO2. We could demonstrate that the COS compensation point, the CA activity and the deposition velocities may change and cause a decrease of the COS uptake by plant ecosystems. As a consequence, the atmospheric COS level may rise leading to higher input of this trace gas into the stratosphere and causing a higher energy reflection by the stratospheric sulfur aerosol into space, thus counteracting the direct radiative forcing by the tropospheric COS.

  20. Fine Spatial Scale Variation of Soil Microbial Communities under European Beech and Norway Spruce

    PubMed Central

    Nacke, Heiko; Goldmann, Kezia; Schöning, Ingo; Pfeiffer, Birgit; Kaiser, Kristin; Castillo-Villamizar, Genis A.; Schrumpf, Marion; Buscot, François; Daniel, Rolf; Wubet, Tesfaye

    2016-01-01

    The complex interactions between trees and soil microbes in forests as well as their inherent seasonal and spatial variations are poorly understood. In this study, we analyzed the effects of major European tree species (Fagus sylvatica L. and Picea abies (L.) Karst) on soil bacterial and fungal communities. Mineral soil samples were collected from different depths (0–10, 10–20 cm) and at different horizontal distances from beech or spruce trunks (0.5, 1.5, 2.5, 3.5 m) in early summer and autumn. We assessed the composition of soil bacterial and fungal communities based on 16S rRNA gene and ITS DNA sequences. Community composition of bacteria and fungi was most strongly affected by soil pH and tree species. Different ectomycorrhizal fungi (e.g., Tylospora) known to establish mutualistic associations with plant roots showed a tree species preference. Moreover, bacterial and fungal community composition showed spatial and seasonal shifts in soil surrounding beech and spruce. The relative abundance of saprotrophic fungi was higher at a depth of 0–10 vs. 10–20 cm depth. This was presumably a result of changes in nutrient availability, as litter input and organic carbon content decreased with soil depth. Overall bacterial community composition showed strong variations under spruce with increasing distance from the tree trunks, which might be attributed in part to higher fine root biomass near spruce trunks. Furthermore, overall bacterial community composition was strongly affected by season under deciduous trees. PMID:28066384

  1. Variation in leaf flushing date influences autumnal senescence and next year’s flushing date in two temperate tree species

    PubMed Central

    Fu, Yongshuo S. H.; Campioli, Matteo; Vitasse, Yann; De Boeck, Hans J.; Van den Berge, Joke; AbdElgawad, Hamada; Asard, Han; Piao, Shilong; Deckmyn, Gaby; Janssens, Ivan A.

    2014-01-01

    Recent temperature increases have elicited strong phenological shifts in temperate tree species, with subsequent effects on photosynthesis. Here, we assess the impact of advanced leaf flushing in a winter warming experiment on the current year’s senescence and next year’s leaf flushing dates in two common tree species: Quercus robur L. and Fagus sylvatica L. Results suggest that earlier leaf flushing translated into earlier senescence, thereby partially offsetting the lengthening of the growing season. Moreover, saplings that were warmed in winter–spring 2009–2010 still exhibited earlier leaf flushing in 2011, even though the saplings had been exposed to similar ambient conditions for almost 1 y. Interestingly, for both species similar trends were found in mature trees using a long-term series of phenological records gathered from various locations in Europe. We hypothesize that this long-term legacy effect is related to an advancement of the endormancy phase (chilling phase) in response to the earlier autumnal senescence. Given the importance of phenology in plant and ecosystem functioning, and the prediction of more frequent extremely warm winters, our observations and postulated underlying mechanisms should be tested in other species. PMID:24799708

  2. Chamber and field evaluations of air pollution tolerances of urban trees

    SciTech Connect

    Karnosky, D.F.

    1981-04-01

    Results are presented for a study of the relative air pollution tolerances of 32 urban-tree cultivars as determined by both chamber fumigations and field exposures. Tolerances to ozone and sulfur dioxide, alone and in combination, were determined using short-term, acute doses administered while the plants were inside a plastic fumigation chamber located inside the Cary Arboretum greenhouses. In a follow-up study still underway, representatives of the same cultivars were outplanted at four locations in the greater New York City area. To date, only oxidant-type injury has been observed on trees in the field plots. Cultivars tolerant to all chamber and field exposures were Acer platanoides Cleveland, Crimson King, Emerald Queen, Jade Glen, and Summershade; Acer rubrum Autumn Flame and Red Sunset; Acer saccharum Green Mountain and Temple's Upright; Fagus sylvatica Rotundifolia; Fraxinus pennsylvanica Summit; and Ginkgo biloba Fastigate and Sentry. Cultivars sensitive to ozone as determined by the chamber and field tests and that may serve as bioindicators of the presence of ozone were Gleditsia triacanthos inermis imperial and Platanus acerifolia Bloodgood.

  3. Stem CO2 efflux in six co-occurring tree species: underlying factors and ecological implications.

    PubMed

    Rodríguez-Calcerrada, Jesús; López, Rosana; Salomón, Roberto; Gordaliza, Guillermo G; Valbuena-Carabaña, María; Oleksyn, Jacek; Gil, Luis

    2015-06-01

    Stem respiration plays a role in species coexistence and forest dynamics. Here we examined the intra- and inter-specific variability of stem CO2 efflux (E) in dominant and suppressed trees of six deciduous species in a mixed forest stand: Fagus sylvatica L., Quercus petraea [Matt.] Liebl, Quercus pyrenaica Willd., Prunus avium L., Sorbus aucuparia L. and Crataegus monogyna Jacq. We conducted measurements in late autumn. Within species, dominants had higher E per unit stem surface area (Es ) mainly because sapwood depth was higher than in suppressed trees. Across species, however, differences in Es corresponded with differences in the proportion of living parenchyma in sapwood and concentration of non-structural carbohydrates (NSC). Across species, Es was strongly and NSC marginally positively related with an index of drought tolerance, suggesting that slow growth of drought-tolerant trees is related to higher NSC concentration and Es . We conclude that, during the leafless period, E is indicative of maintenance respiration and is related with some ecological characteristics of the species, such as drought resistance; that sapwood depth is the main factor explaining variability in Es within species; and that the proportion of NSC in the sapwood is the main factor behind variability in Es among species.

  4. Forest trees filter chronic wind-signals to acclimate to high winds.

    PubMed

    Bonnesoeur, Vivien; Constant, Thiéry; Moulia, Bruno; Fournier, Meriem

    2016-05-01

    Controlled experiments have shown that trees acclimate thigmomorphogenetically to wind-loads by sensing their deformation (strain). However, the strain regime in nature is exposed to a full spectrum of winds. We hypothesized that trees avoid overreacting by responding only to winds which bring information on local climate and/or wind exposure. Additionally, competition for light dependent on tree social status also likely affects thigmomorphogenesis. We monitored and manipulated quantitatively the strain regimes of 15 pairs of beech (Fagus sylvatica) trees of contrasting social status in an acclimated stand, and quantified the effects of these regimes on the radial growth over a vegetative season. Trees exposed to artificial bending, the intensity of which corresponds to the strongest wind-induced strains, enhanced their secondary growth by at least 80%. Surprisingly, this reaction was even greater - relatively - for suppressed trees than for dominant ones. Acclimated trees did not sense the different types of wind events in the same way. Daily wind speed peaks due to thermal winds were filtered out. Thigmomorphogenesis was therefore driven by intense storms. Thigmomorphogenesis is also likely to be involved in determining social status.

  5. Invasion by the Alien Tree Prunus serotina Alters Ecosystem Functions in a Temperate Deciduous Forest.

    PubMed

    Aerts, Raf; Ewald, Michael; Nicolas, Manuel; Piat, Jérôme; Skowronek, Sandra; Lenoir, Jonathan; Hattab, Tarek; Garzón-López, Carol X; Feilhauer, Hannes; Schmidtlein, Sebastian; Rocchini, Duccio; Decocq, Guillaume; Somers, Ben; Van De Kerchove, Ruben; Denef, Karolien; Honnay, Olivier

    2017-01-01

    Alien invasive species can affect large areas, often with wide-ranging impacts on ecosystem structure, function, and services. Prunus serotina is a widespread invader of European temperate forests, where it tends to form homogeneous stands and limits recruitment of indigenous trees. We hypotesized that invasion by P. serotina would be reflected in the nutrient contents of the native species' leaves and in the respiration of invaded plots as efficient resource uptake and changes in nutrient cycling by P. serotina probably underly its aggressive invasiveness. We combined data from 48 field plots in the forest of Compiègne, France, and data from an experiment using 96 microcosms derived from those field plots. We used general linear models to separate effects of invasion by P. serotina on heterotrophic soil and litter respiration rates and on canopy foliar nutrient content from effects of soil chemical properties, litter quantity, litter species composition, and tree species composition. In invaded stands, average respiration rates were 5.6% higher for soil (without litter) and 32% higher for soil and litter combined. Compared to indigenous tree species, P. serotina exhibited higher foliar N (+24.0%), foliar P (+50.7%), and lower foliar C:N (-22.4%) and N:P (-10.1%) ratios. P. serotina affected foliar nutrient contents of co-occuring indigenous tree species leading to decreased foliar N (-8.7 %) and increased C:N ratio (+9.5%) in Fagus sylvatica, decreased foliar N:P ratio in Carpinus betulus (-13.5%) and F. sylvatica (-11.8%), and increased foliar P in Pinus sylvestris (+12.3%) in invaded vs. uninvaded stands. Our results suggest that P. serotina is changing nitrogen, phosphorus, and carbon cycles to its own advantage, hereby increasing carbon turnover via labile litter, affecting the relative nutrient contents in the overstory leaves, and potentially altering the photosynthetic capacity of the long-lived indigenous broadleaved species. Uncontrolled invasion of

  6. Invasion by the Alien Tree Prunus serotina Alters Ecosystem Functions in a Temperate Deciduous Forest

    PubMed Central

    Aerts, Raf; Ewald, Michael; Nicolas, Manuel; Piat, Jérôme; Skowronek, Sandra; Lenoir, Jonathan; Hattab, Tarek; Garzón-López, Carol X.; Feilhauer, Hannes; Schmidtlein, Sebastian; Rocchini, Duccio; Decocq, Guillaume; Somers, Ben; Van De Kerchove, Ruben; Denef, Karolien; Honnay, Olivier

    2017-01-01

    Alien invasive species can affect large areas, often with wide-ranging impacts on ecosystem structure, function, and services. Prunus serotina is a widespread invader of European temperate forests, where it tends to form homogeneous stands and limits recruitment of indigenous trees. We hypotesized that invasion by P. serotina would be reflected in the nutrient contents of the native species' leaves and in the respiration of invaded plots as efficient resource uptake and changes in nutrient cycling by P. serotina probably underly its aggressive invasiveness. We combined data from 48 field plots in the forest of Compiègne, France, and data from an experiment using 96 microcosms derived from those field plots. We used general linear models to separate effects of invasion by P. serotina on heterotrophic soil and litter respiration rates and on canopy foliar nutrient content from effects of soil chemical properties, litter quantity, litter species composition, and tree species composition. In invaded stands, average respiration rates were 5.6% higher for soil (without litter) and 32% higher for soil and litter combined. Compared to indigenous tree species, P. serotina exhibited higher foliar N (+24.0%), foliar P (+50.7%), and lower foliar C:N (−22.4%) and N:P (−10.1%) ratios. P. serotina affected foliar nutrient contents of co-occuring indigenous tree species leading to decreased foliar N (−8.7 %) and increased C:N ratio (+9.5%) in Fagus sylvatica, decreased foliar N:P ratio in Carpinus betulus (−13.5%) and F. sylvatica (−11.8%), and increased foliar P in Pinus sylvestris (+12.3%) in invaded vs. uninvaded stands. Our results suggest that P. serotina is changing nitrogen, phosphorus, and carbon cycles to its own advantage, hereby increasing carbon turnover via labile litter, affecting the relative nutrient contents in the overstory leaves, and potentially altering the photosynthetic capacity of the long-lived indigenous broadleaved species. Uncontrolled

  7. Fine-Scale Spatial Variability of Precipitation, Soil, and Plant Water Isotopes

    NASA Astrophysics Data System (ADS)

    Goldsmith, G. R.; Braun, S.; Romero, C.; Engbersen, N.; Gessler, A.; Siegwolf, R. T.; Schmid, L.

    2015-12-01

    Introduction: The measurement of stable isotope ratios of water has become fundamental in advancing our understanding of environmental patterns and processes, particularly with respect to understanding the movement of water within the soil-plant-atmosphere continuum. While considerable research has explored the temporal variation in stable isotope ratios of water in the environment, our understanding of the spatial variability of these isotopes remains poorly understood. Methods: We collected spatially explicit samples of throughfall and soil water (n=150 locations) from a 1 ha plot delineated in a mixed deciduous forest in the northern Alps of Switzerland. We complemented this with fully sunlit branch and leaf samples (n = 60 individuals) collected from Picea abies and Fagus sylvatica between 14:00 and 16:00 on the same day by means of a helicopter. Soil and plant waters were extracted using cryogenic vacuum distillation and all samples were analyzed for δ18O using an isotope ratio mass spectrometer. Results: The mean δ18O of throughfall (-3.3 ± 0.8‰) indicated some evaporative enrichment associated with passage through the canopy, but this did not significantly differ from the precipitation collected in nearby open sites (-4.05‰). However, soil was depleted (-7.0 ± 1.8‰) compared to throughfall and there was no significant relationship between the two, suggesting that the sampling for precipitation inputs did not capture all the sources (e.g. stream water, which was -11.5‰) contributing to soil water δ18O ratios. Evaporative enrichment of δ18O was higher in leaves of Fagus (14.8 ± 1.8‰) than in leaves of Picea (11.8 ± 1.7‰). Sampling within crowns of each species (n = 5 branches each from 5 individuals) indicated that variability in a single individual is similar to that among individuals. Discussion: Stable isotopes of water are frequently engaged for studies of ecohydrology, plant ecophysiology, and paleoclimatology. Our results help

  8. Upland beech trees significantly contribute to forest methane exchange

    NASA Astrophysics Data System (ADS)

    Machacova, Katerina; Maier, Martin; Svobodova, Katerina; Halaburt, Ellen; Haddad, Sally; Lang, Friederike; Urban, Otmar

    2016-04-01

    Methane (CH4) can be emitted not only from soil, but also from plants. Fluxes of CH4were predominantly investigated in riparian herbaceous plants, whereas studies on trees, particularly those lacking an aerenchyma, are rare. In soil produced CH4 can be taken up by roots, transported via intercellular spaces and the aerenchyma system, or transpiration stream to aboveground plant tissues and released to the atmosphere via lenticels or stomata. Although CH4 might be also produced by microorganisms living in plant tissues or photochemical processes in plants, these processes are relatively minor. It has been shown that seedlings of European beech (Fagus sylvatica) emit CH4 from its stems despite the lack of an aerenchyma. Our objectives were to determine the CH4 fluxes from mature beech trees and adjacent soil under natural field conditions, and to estimate the role of trees in the CH4exchange within the soil-tree-atmosphere continuum. Measurements were conducted in two mountain beech forests with different geographical and climatic conditions (White Carpathians, Czech Republic; Black Forest, Germany). CH4 fluxes at stems (profile) and root bases level were simultaneously measured together with soil-atmosphere fluxes using static chamber systems followed by chromatographic analysis or continuous laser detection of CH4 concentrations. Our study shows that mature beech trees have the ability to exchange CH4 with the atmosphere. The beech stems emitted CH4 into the atmosphere at the White Carpathians site in the range from 2.00 to 179 μg CH4 m-2 stem area h-1, while CH4 flux rates ranged between -1.34 to 1.73 μg CH4 m-2 h-1 at the Black Forest site. The root bases of beech trees from the White Carpathians released CH4 into the atmosphere (from 0.62 to 49.8 μg CH4 m-2 root area h-1), whereas a prevailing deposition was observed in the Black Forest (from -1.21 to 0.81 μg CH4 m-2 h-1). These fluxes seem to be affected by soil water content and its spatial heterogeneity

  9. A multiproxy study of Holocene water-depth and environmental changes in Lake St Ana, Eastern Carpathian Mountains, Romania

    NASA Astrophysics Data System (ADS)

    Magyari, E. K.; Buczkó, K.; Braun, M.; Jakab, G.

    2009-04-01

    This study presents the results of a multi-disciplinary investigation carried out on the sediment of a crater lake (Lake Saint Ana, 950 m a.s.l.) from the Eastern Carpathian Mountains. The lake is set in a base-poor volcanic environment with oligotrophic and slightly acidic water. Loss-on-ignition, major and trace element, pollen, plant macrofossil and siliceous algae analyses were used to reconstruct Holocene environmental and water-depth changes. Diatom-based transfer functions were applied to estimate the lake's trophic status and pH, while reconstruction of the water-depth changes was based on the plant macrofossil and diatom records. The lowest Holocene water-depths were found between 9,000 and 7,400 calibrated BP years, when the crater was occupied by Sphagnum-bog and bog-pools. The major trend from 7,400 years BP was a gradual increase, but the basin was still dominated by poor-fen and poor fen-pools. Significant increases in water-depth, and meso/oligotrophic lake conditions were found from 5,350(1), 3,300(2) and 2,700 years BP. Of these, the first two coincided with major terrestrial vegetation changes, namely the establishment of Carpinus betulus on the crater slope (1), and the replacement of the lakeshore Picea abies forest by Fagus sylvatica (2). The chemical record clearly indicated significant soil changes along with the canopy changes (from coniferous to deciduous), that in turn led to increased in-lake productivity and pH. A further increase in water-depth around 2,700 years BP resulted in stable thermal stratification and hypolimnetic anoxia that via P-release further increased in-lake productivity and eventually led to phytoplankton blooms with large populations of Scenedesmus cf. S. brasiliensis. High productivity was depressed by anthropogenic lakeshore forest clearances commencing from ca. 1,000 years BP that led to the re-establishment of Picea abies on the lakeshore and consequent acidification of the lake-water. On the whole, these data

  10. Transpiration of urban trees and its cooling effect in a high latitude city

    NASA Astrophysics Data System (ADS)

    Konarska, Janina; Uddling, Johan; Holmer, Björn; Lutz, Martina; Lindberg, Fredrik; Pleijel, Håkan; Thorsson, Sofia

    2016-01-01

    An important ecosystem service provided by urban trees is the cooling effect caused by their transpiration. The aim of this study was to quantify the magnitude of daytime and night-time transpiration of common urban tree species in a high latitude city (Gothenburg, Sweden), to analyse the influence of weather conditions and surface permeability on the tree transpiration, and to find out whether tree transpiration contributed to daytime or nocturnal cooling. Stomatal conductance and leaf transpiration at day and night were measured on mature street and park trees of seven common tree species in Gothenburg: Tilia europaea, Quercus robur, Betula pendula, Acer platanoides, Aesculus hippocastanum, Fagus sylvatica and Prunus serrulata. Transpiration increased with vapour pressure deficit and photosynthetically active radiation. Midday rates of sunlit leaves ranged from less than 1 mmol m-2 s-1 ( B. pendula) to over 3 mmol m-2 s-1 ( Q. robur). Daytime stomatal conductance was positively related to the fraction of permeable surfaces within the vertically projected crown area. A simple estimate of available rainwater, comprising of precipitation sum and fractional surface permeability within the crown area, was found to explain 68 % of variation in midday stomatal conductance. Night-time transpiration was observed in all studied species and amounted to 7 and 20 % of midday transpiration of sunlit and shaded leaves, respectively. With an estimated night-time latent heat flux of 24 W m-2, tree transpiration significantly increased the cooling rate around and shortly after sunset, but not later in the night. Despite a strong midday latent heat flux of 206 W m-2, a cooling effect of tree transpiration was not observed during the day.

  11. Fungal Planet description sheets: 281-319.

    PubMed

    Crous, P W; Wingfield, M J; Schumacher, R K; Summerell, B A; Giraldo, A; Gené, J; Guarro, J; Wanasinghe, D N; Hyde, K D; Camporesi, E; Gareth Jones, E B; Thambugala, K M; Malysheva, E F; Malysheva, V F; Acharya, K; Álvarez, J; Alvarado, P; Assefa, A; Barnes, C W; Bartlett, J S; Blanchette, R A; Burgess, T I; Carlavilla, J R; Coetzee, M P A; Damm, U; Decock, C A; den Breeÿen, A; de Vries, B; Dutta, A K; Holdom, D G; Rooney-Latham, S; Manjón, J L; Marincowitz, S; Mirabolfathy, M; Moreno, G; Nakashima, C; Papizadeh, M; Shahzadeh Fazeli, S A; Amoozegar, M A; Romberg, M K; Shivas, R G; Stalpers, J A; Stielow, B; Stukely, M J C; Swart, W J; Tan, Y P; van der Bank, M; Wood, A R; Zhang, Y; Groenewald, J Z

    2014-12-01

    Novel species of fungi described in the present study include the following from South Africa: Alanphillipsia aloeicola from Aloe sp., Arxiella dolichandrae from Dolichandra unguiscati, Ganoderma austroafricanum from Jacaranda mimosifolia, Phacidiella podocarpi and Phaeosphaeria podocarpi from Podocarpus latifolius, Phyllosticta mimusopisicola from Mimusops zeyheri and Sphaerulina pelargonii from Pelargonium sp. Furthermore, Barssia maroccana is described from Cedrus atlantica (Morocco), Codinaea pini from Pinus patula (Uganda), Crucellisporiopsis marquesiae from Marquesia acuminata (Zambia), Dinemasporium ipomoeae from Ipomoea pes-caprae (Vietnam), Diaporthe phragmitis from Phragmites australis (China), Marasmius vladimirii from leaf litter (India), Melanconium hedericola from Hedera helix (Spain), Pluteus albotomentosus and Pluteus extremiorientalis from a mixed forest (Russia), Rachicladosporium eucalypti from Eucalyptus globulus (Ethiopia), Sistotrema epiphyllum from dead leaves of Fagus sylvatica in a forest (The Netherlands), Stagonospora chrysopyla from Scirpus microcarpus (USA) and Trichomerium dioscoreae from Dioscorea sp. (Japan). Novel species from Australia include: Corynespora endiandrae from Endiandra introrsa, Gonatophragmium triuniae from Triunia youngiana, Penicillium coccotrypicola from Archontophoenix cunninghamiana and Phytophthora moyootj from soil. Novelties from Iran include Neocamarosporium chichastianum from soil and Seimatosporium pistaciae from Pistacia vera. Xenosonderhenia eucalypti and Zasmidium eucalyptigenum are newly described from Eucalyptus urophylla in Indonesia. Diaporthe acaciarum and Roussoella acacia are newly described from Acacia tortilis in Tanzania. New species from Italy include Comoclathris spartii from Spartium junceum and Phoma tamaricicola from Tamarix gallica. Novel genera include (Ascomycetes): Acremoniopsis from forest soil and Collarina from water sediments (Spain), Phellinocrescentia from a Phellinus sp. (French

  12. Species-specific allometric scaling under self-thinning: evidence from long-term plots in forest stands.

    PubMed

    Pretzsch, Hans

    2006-01-01

    Experimental plots covering a 120 years' observation period in unthinned, even-aged pure stands of common beech (Fagus sylvatica), Norway spruce (Picea abies), Scots pine (Pinus sylvestris), and common oak (Quercus Petraea) are used to scrutinize Reineke's (1933) empirically derived stand density rule [see text], N=tree number per unit area, [see text]=mean stem diameter), Yoda's (1963) self-thinning law based on Euclidian geometry ([see text] [see text]=mean biomass per tree), and basic assumptions of West, Brown and Enquist's (1997, 1999) fractal scaling rules ([see text] [see text] w=biomass per tree, d=stem diameter). RMA and OLS regression provides observed allometric exponents, which are tested against the exponents, expected by the considered rules. Hope for a consistent scaling law fades away, as observed exponents significantly correspond with the considered rules only in a minority of cases: (1) exponent r of [see text] varies around Reineke's constant -1.605, but is significantly different from r=-2, supposed by Euclidian or fractal scaling, (2) Exponent c of the self-thinning line [see text] roams roughly about the Euclidian scaling constant -3/2, (3) Exponent a of [see text] tends to follow fractal scaling 8/3. The unique dataset's evaluation displays that (4) scaling exponents and their oscillation are species-specific, (5) Euclidian scaling of one relation and fractal scaling of another are coupled, depending on species. Ecological implications of the results in respect to self-tolerance (common oak>Norway spruce>Scots pine>common beech) and efficiency of space occupation (common beech>Scots pine>Norway spruce>common oak) are stressed and severe consequences for assessing, regulating and scheduling stand density are discussed.

  13. Effect of Leaf Litter Diversity on Dissolved Organic Matter Export in a Deciduous Forest Soil

    NASA Astrophysics Data System (ADS)

    Scheibe*, A.; Eißfeller, V.; Langenbruch, C.; Seven, J.; Gleixner, G.

    2012-04-01

    We investigated sources and fate of dissolved organic matter (DOM) in soils in order to understand the effect of tree diversity on below ground processes. We established a leaf litter exchange experiment in the National Park Hainich (Thuringia, Germany) in December 2008. Labeled (13C) and unlabeled leaf litter of beach (Fagus sylvatica) and ash (Fraxinus excelsior) were exposed to study the decomposition process. Soil water was collected biweekly with glass suction plates (1 μm pore size, UMS, Munich, Germany) in 5 cm soil depth and pH, conductivity, DOC and anions (Cl-, NO3-, NO2-, PO43-, SO42-, F-) were determined. The 13DOC values were measured using high performance liquid chromatography - isotope ratio mass spectrometry (HPLC-IRMS). The values of conductivity and pH in the soil water indicate slower decomposition processes for leaf litter of beech in comparison to ash leaf litter. The conductivity was correlated with the Cl- ion during the first spring, which suggests the export of carbon due to leaching processes. However during the summer the conductivity correlated with the NO3- ions, which indicates mineralization as driving process. Surprisingly, the contribution of litter 13C into the dissolved carbon pool was very low. The highest contribution with up to 8.6% DOC labeled by ash litter derived carbon was found in the first 3 month of application. However, in the mean only 1.2% and 2.6% of DOC was labeled by carbon of the beech and ash litter, respectively. This represents in total only up to 0.41% of labeled litter carbon that was added. The higher percentages of ash litter derived 13C in DOM of soil water compared to beech indicates a positive effect of litter quality on decomposition. However, we did not find a faster decomposition or higher ash litter derived carbon export in mixed (ash and beech litter) treatments, which would indicate food selection or biodiversity effects.

  14. Effects of stoichiometry and temperature perturbations on beech litter decomposition, enzyme activities and protein expression

    NASA Astrophysics Data System (ADS)

    Keiblinger, K. M.; Schneider, T.; Roschitzki, B.; Schmid, E.; Eberl, L.; Hämmerle, I.; Leitner, S.; Richter, A.; Wanek, W.; Riedel, K.; Zechmeister-Boltenstern, S.

    2011-12-01

    Microbes are major players in leaf litter decomposition and therefore advances in the understanding of their control on element cycling are of paramount importance. Our aim was to investigate the influence of leaf litter stoichiometry in terms of carbon (C) : nitrogen (N) : phosphorus (P) on the decomposition process, and to follow changes in microbial community structure and function in response to temperature-stress treatments. To elucidate how the stoichiometry of beech litter (Fagus sylvatica L.) and stress treatments interactively affect the decomposition processes, a terrestrial microcosm experiment was conducted. Beech litter from different Austrian sites covering C:N ratios from 39 to 61 and C:P ratios from 666 to 1729 were incubated at 15 °C and 60% moisture for six months. Part of the microcosms were then subjected to severe changes in temperature (+30 °C and -15 °C) to monitor the influence of temperature stress. Extracellular enzyme activities were assayed and respiratory activities measured. A semi-quantitative metaproteomics approach (1D-SDS PAGE combined with liquid chromatography and tandem mass-spectrometry; unique spectral counting) was employed to investigate the impact of the applied stress treatments in dependency of litter stoichiometry on structure and function of the decomposing community. In litter with narrow C:nutrient ratios microbial decomposers were most abundant. Cellulase, chitinase, phosphatase and protease activity decreased after heat and frost treatments. Decomposer communities and specific functions varied with site i.e. stoichiometry. The applied stress evoked strong changes of enzyme activities, dissolved organic nitrogen and litter pH. Freeze treatments resulted in a decline in residual plant litter material, and increased fungal abundance indicating slightly accelerated decomposition. Overall, we could detect a strong effect of litter stoichiometry on microbial community structure as well as function. Temperature

  15. Tree species diversity interacts with elevated CO2 to induce a greater root system response.

    PubMed

    Smith, Andrew R; Lukac, Martin; Bambrick, Michael; Miglietta, Franco; Godbold, Douglas L

    2013-01-01

    As a consequence of land-use change and the burning of fossil fuels, atmospheric concentrations of CO2 are increasing and altering the dynamics of the carbon cycle in forest ecosystems. In a number of studies using single tree species, fine root biomass has been shown to be strongly increased by elevated CO2 . However, natural forests are often intimate mixtures of a number of co-occurring species. To investigate the interaction between tree mixture and elevated CO2 , Alnus glutinosa, Betula pendula and Fagus sylvatica were planted in areas of single species and a three species polyculture in a free-air CO2 enrichment study (BangorFACE). The trees were exposed to ambient or elevated CO2 (580 μmol mol(-1) ) for 4 years. Fine and coarse root biomass, together with fine root turnover and fine root morphological characteristics were measured. Fine root biomass and morphology responded differentially to the elevated CO2 at different soil depths in the three species when grown in monocultures. In polyculture, a greater response to elevated CO2 was observed in coarse roots to a depth of 20 cm, and fine root area index to a depth of 30 cm. Total fine root biomass was positively affected by elevated CO2 at the end of the experiment, but not by species diversity. Our data suggest that existing biogeochemical cycling models parameterized with data from species grown in monoculture may be underestimating the belowground response to global change.

  16. The outcome of ecosystem manipulation by elevating atmospheric CO2 is influenced by tree identity and mixture

    NASA Astrophysics Data System (ADS)

    Godbold, Douglas; Smith, Andrew; Lukac, Martin

    2013-04-01

    Free Air Carbon dioxide Enrichment (FACE) has often been used predict the response of forest ecosystems to a future high CO2 world. Many of these investigations have been restricted to exposure of single species or genotypes to elevated CO2. To investigate the interaction between tree mixture and elevated CO2, Alnus glutinosa, Betula pendula and Fagus sylvatica were planted in areas of single species and a three species polyculture in a free-air CO2 enrichment study (BangorFACE). The trees were exposed to ambient or elevated CO2 for 4 years. Aboveground woody biomass was increased in polyculture under both ambient and elevated CO2, but the response to elevated CO2 was smaller in polyculture than in the monocultures. In some years, a longer leaf retention was shown under high CO2, and is an indication that environmental factors may moderate tree response to high CO2. Fine and coarse root biomass, together with fine root turnover and fine root morphological characteristics were also measured. Fine root biomass and morphology responded differentially to the elevated CO2 at different soil depths in the three species when grown in monocultures. In polyculture, a greater response to elevated CO2 was observed in coarse roots, and fine root area index. Total fine root biomass was positively affected by elevated CO2 at the end of the experiment, but not by species diversity. Our results show that the aboveground and belowground response to elevated CO2 is significantly affected by intra- and inter-specific competition, and that elevated CO2 response may be reduced in forest communities comprised of tree species with contrasting functional traits but also that other environmental factors may induce previously unseen effects.

  17. Climate change triggers effects of fungal pathogens and insect herbivores on litter decomposition

    NASA Astrophysics Data System (ADS)

    Butenschoen, Olaf; Scheu, Stefan

    2014-10-01

    Increasing infestation by insect herbivores and pathogenic fungi in response to climate change will inevitably impact the amount and quality of leaf litter inputs into the soil. However, little is known on the interactive effect of infestation severity and climate change on litter decomposition, and no such study has been published for deciduous forests in Central Europe. We assessed changes in initial chemical quality of beech (Fagus sylvatica L.) and maple litter (Acer platanoides L.) in response to infestation by the gall midge Mikiola fagi Hart. and the pathogenic fungus Sawadaea tulasnei Fuckel, respectively, and investigated interactive effects of infestation severity, changes in temperature and soil moisture on carbon mineralization in a short-term laboratory study. We found that infestation by the gall midge M. fagi and the pathogenic fungus S. tulasnei significantly changed the chemical quality of beech and maple litter. Changes in element concentrations were generally positive and more pronounced, and if negative less pronounced for maple than beech litter most likely due to high quality fungal tissue remaining on litter after abscission. More importantly, alterations in litter chemical quality did not translate to distinct patterns of carbon mineralization at ambient conditions, but even low amounts of infested litter accelerated carbon mineralization at moderately increased soil moisture and in particular at higher temperature. Our results indicate that insect herbivores and fungal pathogens can markedly alter initial litter chemical quality, but that afterlife effects on carbon mineralization depend on soil moisture and temperature, suggesting that increased infestation severity under projected climate change potentially increases soil carbon release in deciduous forests in Central Europe.

  18. Influence of Litter Diversity on Dissolved Organic Matter Release and Soil Carbon Formation in a Mixed Beech Forest

    PubMed Central

    Scheibe, Andrea; Gleixner, Gerd

    2014-01-01

    We investigated the effect of leaf litter on below ground carbon export and soil carbon formation in order to understand how litter diversity affects carbon cycling in forest ecosystems. 13C labeled and unlabeled leaf litter of beech (Fagus sylvatica) and ash (Fraxinus excelsior), characterized by low and high decomposability, were used in a litter exchange experiment in the Hainich National Park (Thuringia, Germany). Litter was added in pure and mixed treatments with either beech or ash labeled with 13C. We collected soil water in 5 cm mineral soil depth below each treatment biweekly and determined dissolved organic carbon (DOC), δ13C values and anion contents. In addition, we measured carbon concentrations and δ13C values in the organic and mineral soil (collected in 1 cm increments) up to 5 cm soil depth at the end of the experiment. Litter-derived C contributes less than 1% to dissolved organic matter (DOM) collected in 5 cm mineral soil depth. Better decomposable ash litter released significantly more (0.50±0.17%) litter carbon than beech litter (0.17±0.07%). All soil layers held in total around 30% of litter-derived carbon, indicating the large retention potential of litter-derived C in the top soil. Interestingly, in mixed (ash and beech litter) treatments we did not find a higher contribution of better decomposable ash-derived carbon in DOM, O horizon or mineral soil. This suggest that the known selective decomposition of better decomposable litter by soil fauna has no or only minor effects on the release and formation of litter-derived DOM and soil organic matter. Overall our experiment showed that 1) litter-derived carbon is of low importance for dissolved organic carbon release and 2) litter of higher decomposability is faster decomposed, but litter diversity does not influence the carbon flow. PMID:25486628

  19. Forest understory plant and soil microbial response to an experimentally induced drought and heat-pulse event: the importance of maintaining the continuum.

    PubMed

    von Rein, Isabell; Gessler, Arthur; Premke, Katrin; Keitel, Claudia; Ulrich, Andreas; Kayler, Zachary E

    2016-08-01

    Drought duration and intensity are expected to increase with global climate change. How changes in water availability and temperature affect the combined plant-soil-microorganism response remains uncertain. We excavated soil monoliths from a beech (Fagus sylvatica L.) forest, thus keeping the understory plant-microbe communities intact, imposed an extreme climate event, consisting of drought and/or a single heat-pulse event, and followed microbial community dynamics over a time period of 28 days. During the treatment, we labeled the canopy with (13) CO2 with the goal of (i) determining the strength of plant-microbe carbon linkages under control, drought, heat and heat-drought treatments and (ii) characterizing microbial groups that are tightly linked to the plant-soil carbon continuum based on (13) C-labeled PLFAs. Additionally, we used 16S rRNA sequencing of bacteria from the Ah horizon to determine the short-term changes in the active microbial community. The treatments did not sever within-plant transport over the experiment, and carbon sinks belowground were still active. Based on the relative distribution of labeled carbon to roots and microbial PLFAs, we determined that soil microbes appear to have a stronger carbon sink strength during environmental stress. High-throughput sequencing of the 16S rRNA revealed multiple trajectories in microbial community shifts within the different treatments. Heat in combination with drought had a clear negative effect on microbial diversity and resulted in a distinct shift in the microbial community structure that also corresponded to the lowest level of label found in the PLFAs. Hence, the strongest changes in microbial abundances occurred in the heat-drought treatment where plants were most severely affected. Our study suggests that many of the shifts in the microbial communities that we might expect from extreme environmental stress will result from the plant-soil-microbial dynamics rather than from direct effects of

  20. Trends in wild food plants uses in Gorbeialdea (Basque Country).

    PubMed

    Menendez-Baceta, Gorka; Pardo-de-Santayana, Manuel; Aceituno-Mata, Laura; Tardío, Javier; Reyes-García, Victoria

    2017-05-01

    Despite wild food plants' potential nutritional and economic value, their knowledge and consumption is quickly decreasing throughout the world. We examine how the consideration that a wild plant use is within the cultural tradition of a given area relates to its consumption by analysing 1) current perception and 2) past and present use of six wild plants' food-uses, of which only three are locally perceived as being part of the local tradition. Research was conducted in Gorbeialdea, an area in the Basque Country with a clearly marked Basque identity opposed to the Spanish identity. Overall, there is a clear decrease in the knowledge and consumption of the selected uses and especially of the three uses acquired from local sources (i.e., the consumption of the raw leaves of Fagus sylvatica and Rumex acetosa and of the fruits of Pyrus cordata). The trend is likely driven by the disappearance of the traditional agrarian lifestyle. Among the uses not acquired from local sources, the use recently adopted from another Basque-speaking area (i.e., macerating the fruits of Prunus spinosa to elaborate a liqueur) is now considered part of the local tradition by young generations, whereas the use acquired from southern Spanish migrants (i.e., using Laurus nobilis leaves as condiments) is not. While lifestyle changes largely explain overall trends in wild edibles consumption, other cultural aspects -in our case study the stigmatization of a given source of information associated to cultural identity- might help shape which new uses of wild plants become embedded in local traditions.

  1. Linking Remotely Sensed Functional Diversity of Structural Traits to the Radiative Regime of a Temperate Mixed Forest

    NASA Astrophysics Data System (ADS)

    Schneider, F. D.; Morsdorf, F.; Furrer, R.; Schmid, B.; Schaepman, M. E.

    2015-12-01

    Patterns of functional diversity reflect the inter- and intraspecific variability of plant traits and are linked to other aspects of biodiversity, environmental factors and ecosystem function. To study the patterns at plot and stand level, spatially continuous trait measurements are required. Remote sensing methods based on airborne observations can offer such continuous high-resolution measurements, resolving individual trees of a forest at a regional extent. The study was performed at the Laegern forest, a temperate mixed forest dominated by deciduous and coniferous trees (Fagus sylvatica, Picea abies; 47°28'42.0" N, 8°21'51.8" E, 682 m asl; Switzerland). Canopy height, plant area index and foliage height diversity were derived from full-waveform airborne laser scanning data. These structural traits were used to calculate functional richness, functional evenness and functional divergence at a range of scales. A Bayesian multiresolution scale analysis was used to infer the scales at which functional diversity patterns occur. The radiative regime of the forest was simulated using the 3D radiative transfer model DART. Using a voxel-based forest reconstruction allowed us to derive top of canopy, bottom of canopy and absorbed photosynthetically active radiation. The results of this study will provide new insights on linking forest canopy structure to the radiative regime of the forest. Light availability is a critical factor determining plant growth and competition. Within canopy light scattering is mainly driven by the arrangement of leaves and their leaf optical properties. Therefore, we expect a link between the structural complexity of the forest as encompassed by functional diversity and the light availability within and below the canopy. Ultimately, this information can be used in dynamic ecosystem models such as ED2, allowing us to predict the influence of functional diversity and radiative properties on ecosystem functioning under current conditions and

  2. On the influence of provenance to soil quality enhanced stress reaction of young beech trees to summer drought.

    PubMed

    Buhk, Constanze; Kämmer, Marcel; Beierkuhnlein, Carl; Jentsch, Anke; Kreyling, Jürgen; Jungkunst, Hermann F

    2016-11-01

    Climate projections propose that drought stress will become challenging for establishing trees. The magnitude of stress is dependent on tree species, provenance, and most likely also highly influenced by soil quality. European Beech (Fagus sylvatica) is of major ecological and economical importance in Central European forests. The species has an especially wide physiological and ecological amplitude enabling growth under various soil conditions within its distribution area in Central Europe. We studied the effects of extreme drought on beech saplings (second year) of four climatically distinct provenances growing on different soils (sandy loam and loamy sand) in a full factorial pot experiment. Foliar δ(13)C, δ(15)N, C, and N as well as above- and belowground growth parameters served as measures for stress level and plant growth. Low-quality soil enhanced the effect of drought compared with qualitatively better soil for the above- and belowground growth parameters, but foliar δ(13)C values revealed that plant stress was still remarkable in loamy soil. For beeches of one provenance, negative sandy soil effects were clearly smaller than for the others, whereas for another provenance drought effects in sandy soil were sometimes fatal. Foliar δ(15)N was correlated with plant size during the experiment. Plasticity of beech provenances in their reaction to drought versus control conditions varied clearly. Although a general trend of declining growth under control or drought conditions in sandy soil was found compared to loamy soil, the magnitude of the effect of soil quality was highly provenance specific. Provenances seemed to show adaptations not only to drought but also to soil quality. Accordingly, scientists should integrate information about climatic pre-adaptation and soil quality within the home range of populations for species distribution modeling and foresters should evaluate soil quality and climatic parameters when choosing donor populations for

  3. Impact of interspecific competition and drought on the allocation of new assimilates in trees.

    PubMed

    Hommel, R; Siegwolf, R; Zavadlav, S; Arend, M; Schaub, M; Galiano, L; Haeni, M; Kayler, Z E; Gessler, A

    2016-09-01

    In trees, the interplay between reduced carbon assimilation and the inability to transport carbohydrates to the sites of demand under drought might be one of the mechanisms leading to carbon starvation. However, we largely lack knowledge on how drought effects on new assimilate allocation differ between species with different drought sensitivities and how these effects are modified by interspecific competition. We assessed the fate of (13) C labelled assimilates in above- and belowground plant organs and in root/rhizosphere respired CO2 in saplings of drought-tolerant Norway maple (Acer platanoides) and drought-sensitive European beech (Fagus sylvatica) exposed to moderate drought, either in mono- or mixed culture. While drought reduced stomatal conductance and photosynthesis rates in both species, both maintained assimilate transport belowground. Beech even allocated more new assimilate to the roots under moderate drought compared to non-limited water supply conditions, and this pattern was even more pronounced under interspecific competition. Even though maple was a superior competitor compared to beech under non-limited soil water conditions, as indicated by the changes in above- and belowground biomass of both species in the interspecific competition treatments, we can state that beech was still able to efficiently allocate new assimilate belowground under combined drought and interspecific competition. This might be seen as a strategy to maintain root osmotic potential and to prioritise root functioning. Our results thus show that beech tolerates moderate drought stress plus competition without losing its ability to supply belowground tissues. It remains to be explored in future work if this strategy is also valid during long-term drought exposure.

  4. Phytophthora morindae, a new species causing black flag disease on noni (Morinda citrifolia L) in Hawaii.

    PubMed

    Nelson, Scot C; Abad, Z Gloria

    2010-01-01

    A homothallic, papillate Phytophthora species causing foliar and fruit blight of noni (Morinda citrifolia var. citrifolia) in Hawaii was identified. The asexual phase of this species is characterized by the production of umbellate sporangiophores and papillate sporangia that are ellipsoid and obpyriform with conspicuously tapered bases and possess caducous, medium to long pedicels. The sexual phase is characterized by the production of oogonia with tapered bases, small amphigynous antheridia and thick-walled, plerotic oospores. The morphology of the taxon does not match any of the valid 95 Phytophthora species described to date. Phylogenetic analysis based on sequences of the internal transcribed spacer rDNA region (ITS) and the translation elongation factor 1 alpha (EF-1 alpha) of this taxon and those from other Phytophthora species from GenBank and the Phytophthora database indicates that the new taxon is most closely related to species in ITS clade 10, including P. kernoviae, P. boehmeriae and the recently described P. gallica. The most closely related species is P. kernoviae, an invasive plant pathogen causing bleeding stem lesions on forest trees (beech, Fagus sylvatica) and foliar necrosis of ornamentals (rhododendron, pieris and magnolia) in the UK, and isolated in New Zealand from necrotic cherimoya shoots and fruits and soil. Although the morphological characters of the sexual phase of P. morindae and P. kernoviae are similar, the umbellate sporangiophores produced by the new taxon marks the main morphological distinction. In this paper we describe the morphological characteristics, the phylogenetic relationships and pathogenicity characteristics that support the description of this taxon as a new species with the proposed name Phytophthora morindae sp. nov.

  5. Sapling herbivory, invertebrate herbivores and predators across a natural tree diversity gradient in Germany's largest connected deciduous forest.

    PubMed

    Sobek, Stephanie; Scherber, Christoph; Steffan-Dewenter, Ingolf; Tscharntke, Teja

    2009-05-01

    Tree species-rich forests are hypothesised to be less susceptible to insect herbivores, but so far herbivory-diversity relationships have rarely been tested for tree saplings, and no such study has been published for deciduous forests in Central Europe. We expected that diverse tree communities reduce the probability of detection of host plants and increase abundance of predators, thereby reducing herbivory. We examined levels of herbivory suffered by beech (Fagus sylvatica L.) and maple saplings (Acer pseudoplatanus L. and Acer platanoides L.) across a tree species diversity gradient within Germany's largest remaining deciduous forest area, and investigated whether simple beech or mixed stands were less prone to damage caused by herbivorous insects. Leaf area loss and the frequency of galls and mines were recorded for 1,040 saplings (>13,000 leaves) in June and August 2006. In addition, relative abundance of predators was assessed to test for potential top-down control. Leaf area loss was generally higher in the two species of maple compared to beech saplings, while only beech showed a decline in damage caused by leaf-chewing herbivores across the tree diversity gradient. No significant patterns were found for galls and mines. Relative abundance of predators on beech showed a seasonal response and increased on species-rich plots in June, suggesting higher biological control. We conclude that, in temperate deciduous forests, herbivory-tree diversity relationships are significant, but are tree species-dependent with bottom-up and top-down control as possible mechanisms. In contrast to maple, beech profits from growing in a neighbourhood of higher tree richness, which implies that species identity effects may be of greater importance than tree diversity effects per se. Hence, herbivory on beech appeared to be mediated bottom-up by resource concentration in the sampled forest stands, as well as regulated top-down through biocontrol by natural enemies.

  6. Soil Parameters Drive the Structure, Diversity and Metabolic Potentials of the Bacterial Communities Across Temperate Beech Forest Soil Sequences.

    PubMed

    Jeanbille, M; Buée, M; Bach, C; Cébron, A; Frey-Klett, P; Turpault, M P; Uroz, S

    2016-02-01

    Soil and climatic conditions as well as land cover and land management have been shown to strongly impact the structure and diversity of the soil bacterial communities. Here, we addressed under a same land cover the potential effect of the edaphic parameters on the soil bacterial communities, excluding potential confounding factors as climate. To do this, we characterized two natural soil sequences occurring in the Montiers experimental site. Spatially distant soil samples were collected below Fagus sylvatica tree stands to assess the effect of soil sequences on the edaphic parameters, as well as the structure and diversity of the bacterial communities. Soil analyses revealed that the two soil sequences were characterized by higher pH and calcium and magnesium contents in the lower plots. Metabolic assays based on Biolog Ecoplates highlighted higher intensity and richness in usable carbon substrates in the lower plots than in the middle and upper plots, although no significant differences occurred in the abundance of bacterial and fungal communities along the soil sequences as assessed using quantitative PCR. Pyrosequencing analysis of 16S ribosomal RNA (rRNA) gene amplicons revealed that Proteobacteria, Acidobacteria and Bacteroidetes were the most abundantly represented phyla. Acidobacteria, Proteobacteria and Chlamydiae were significantly enriched in the most acidic and nutrient-poor soils compared to the Bacteroidetes, which were significantly enriched in the soils presenting the higher pH and nutrient contents. Interestingly, aluminium, nitrogen, calcium, nutrient availability and pH appeared to be the best predictors of the bacterial community structures along the soil sequences.

  7. Identification, distribution, and quantification of biominerals in a deciduous forest.

    PubMed

    Krieger, C; Calvaruso, C; Morlot, C; Uroz, S; Salsi, L; Turpault, M-P

    2017-03-01

    Biomineralization is a common process in most vascular plants, but poorly investigated for trees. Although the presence of calcium oxalate and silica accumulation has been reported for some tree species, the chemical composition, abundance, and quantification of biominerals remain poorly documented. However, biominerals may play important physiological and structural roles in trees, especially in forest ecosystems, which are characterized by nutrient-poor soils. In this context, our study aimed at investigating the morphology, distribution, and relative abundance of biominerals in the different vegetative compartments (foliage, branch, trunk, and root) of Fagus sylvatica L. and Acer pseudoplatanus L. using a combination of scanning electron microscopy and tomography analyses. Biomineral crystallochemistry was assessed by X-ray diffraction and energy-dispersive X-ray analyses, while calcium, silicon, and oxalic acid were quantified in the compartments and at the forest scale. Our analyses revealed that biominerals occurred as crystals or coating layers mostly in bark and leaves and were identified as opal, whewellite, and complex biominerals. In both tree species, opal was mostly found in the external tissues of trunk, branch, and leaves, but also in the roots of beech. In the stand, opal represents around 170 kg/ha. Whewellite was found to suit to conductive tissues (i.e., axial phloem parenchyma, vascular bundles, vessel element) in all investigated compartments of the two tree species. The shape of whewellite was prismatic and druses in beech, and almost all described shapes were seen in sycamore maple. Notably, the amount of whewellite was strongly correlated with the total calcium in all investigated compartments whatever the tree species is, suggesting a biologic control of whewellite precipitation. The amount of whewellite in the aboveground biomass of Montiers forest was more important than that of opal and was around 1170 kg/ha. Therefore, biominerals

  8. Comparative measurements of transpiration and canopy conductance in two mixed deciduous woodlands differing in structure and species composition.

    PubMed

    Herbst, Mathias; Rosier, Paul T W; Morecroft, Michael D; Gowing, David J

    2008-06-01

    Transpiration of two heterogeneous broad-leaved woodlands in southern England was monitored by the sap flux technique throughout the 2006 growing season. Grimsbury Wood, which had a leaf area index (LAI) of 3.9, was dominated by oak (Quercus robur L.) and birch (Betula pubescens L.) and had a continuous hazel (Corylus avellana L.) understory. Wytham Woods, which had an LAI of 3.6, was dominated by ash (Fraxinus excelsior L.) and sycamore (Acer pseudoplatanus L.) and had only a sparse understory. Annual canopy transpiration was 367 mm for Grimsbury Wood and 397 mm for Wytham Woods. These values were similar to those for beech (Fagus sylvatica L.) plantations in the same region, and differ from one another by less than the typical margin of uncertainty of the sap flux technique. Canopy conductance (g(c)), calculated for both woodlands by inverting the Penman-Monteith equation, was related to incoming solar radiation (R(G)) and the vapor pressure deficit (D). The response of g(c) to R(G) was similar for both forests. Both reference conductance (g(cref)), defined as g(c) at D=1 kPa, and stomatal sensitivity (-m), defined as the slope of the logarithmic response curve of g(c) to D, increased during the growing season at Wytham Woods but not at Grimsbury Wood. The -m/g(cref) ratio was significantly lower at Wytham Woods than at Grimsbury Wood and was insufficient to keep the difference between leaf and soil water potentials constant, according to a simple hydraulic model. This meant that annual water consumption of the two woodlands was similar despite different regulatory mechanisms and associated short-term variations in canopy transpiration. The -m/g(cref) ratio depended on the range of D under which the measurements were made. This was shown to be particularly important for studies conducted under low and narrow ranges of D.

  9. Influence of litter diversity on dissolved organic matter release and soil carbon formation in a mixed beech forest.

    PubMed

    Scheibe, Andrea; Gleixner, Gerd

    2014-01-01

    We investigated the effect of leaf litter on below ground carbon export and soil carbon formation in order to understand how litter diversity affects carbon cycling in forest ecosystems. 13C labeled and unlabeled leaf litter of beech (Fagus sylvatica) and ash (Fraxinus excelsior), characterized by low and high decomposability, were used in a litter exchange experiment in the Hainich National Park (Thuringia, Germany). Litter was added in pure and mixed treatments with either beech or ash labeled with 13C. We collected soil water in 5 cm mineral soil depth below each treatment biweekly and determined dissolved organic carbon (DOC), δ13C values and anion contents. In addition, we measured carbon concentrations and δ13C values in the organic and mineral soil (collected in 1 cm increments) up to 5 cm soil depth at the end of the experiment. Litter-derived C contributes less than 1% to dissolved organic matter (DOM) collected in 5 cm mineral soil depth. Better decomposable ash litter released significantly more (0.50±0.17%) litter carbon than beech litter (0.17±0.07%). All soil layers held in total around 30% of litter-derived carbon, indicating the large retention potential of litter-derived C in the top soil. Interestingly, in mixed (ash and beech litter) treatments we did not find a higher contribution of better decomposable ash-derived carbon in DOM, O horizon or mineral soil. This suggest that the known selective decomposition of better decomposable litter by soil fauna has no or only minor effects on the release and formation of litter-derived DOM and soil organic matter. Overall our experiment showed that 1) litter-derived carbon is of low importance for dissolved organic carbon release and 2) litter of higher decomposability is faster decomposed, but litter diversity does not influence the carbon flow.

  10. Effects of a triazole fungicide and a pyrethroid insecticide on the decomposition of leaves in the presence or absence of macroinvertebrate shredders.

    PubMed

    Rasmussen, Jes Jessen; Monberg, Rikke Juul; Baattrup-Pedersen, Annette; Cedergreen, Nina; Wiberg-Larsen, Peter; Strobel, Bjarne; Kronvang, Brian

    2012-08-15

    Previously, laboratory experiments have revealed that freely diluted azole fungicides potentiate the direct toxic effect of pyrethroid insecticides on Daphnia magna. More ecologically relevant exposure scenarios where pesticides are adsorbed have not been addressed. In this study we exposed beech leaves (Fagus sylvatica) to the azole fungicide propiconazole (50 or 500 μg L(-1)), the pyrethroid insecticide alpha-cypermethrin (0.1 or 1 μg L(-1)) or any combination of the two for 3h. Exposed leaves were transferred to aquaria with or without an assemblage of macroinvertebrate shredders, and we studied treatment effects on rates of microbial leaf decomposition, microbial biomass (using C:N ratio as a surrogate measure) and macroinvertebrate shredding activity during 26 days post-exposure. Microbial leaf decomposition rates were significantly reduced in the propiconazole treatments, and the reduction in microbial activity was significantly correlated with loss of microbial biomass (increased C:N ratio). Macroinvertebrate shredding activity was significantly reduced in the alpha-cypermethrin treatments. In addition, the macroinvertebrate assemblage responded to the propiconazole treatments by increasing their consumption of leaf litter with lower microbial biomass, probably to compensate for the reduced nutritional quality of this leaf litter. We found no interaction between the two pesticides on macroinvertebrate shredding activity, using Independent Action as a reference model. In terms of microbial leaf decomposition rates, however, alpha-cypermethrin acted as an antagonist on propiconazole. Based on these results we emphasise the importance of considering indirect effects of pesticides in the risk assessment of surface water ecosystems.

  11. Past and future evolution of Abies alba forests in Europe - comparison of a dynamic vegetation model with palaeo data and observations.

    PubMed

    Ruosch, Melanie; Spahni, Renato; Joos, Fortunat; Henne, Paul D; van der Knaap, Willem O; Tinner, Willy

    2016-02-01

    Information on how species distributions and ecosystem services are impacted by anthropogenic climate change is important for adaptation planning. Palaeo data suggest that Abies alba formed forests under significantly warmer-than-present conditions in Europe and might be a native substitute for widespread drought-sensitive temperate and boreal tree species such as beech (Fagus sylvatica) and spruce (Picea abies) under future global warming conditions. Here, we combine pollen and macrofossil data, modern observations, and results from transient simulations with the LPX-Bern dynamic global vegetation model to assess past and future distributions of A. alba in Europe. LPX-Bern is forced with climate anomalies from a run over the past 21 000 years with the Community Earth System Model, modern climatology, and with 21st-century multimodel ensemble results for the high-emission RCP8.5 and the stringent mitigation RCP2.6 pathway. The simulated distribution for present climate encompasses the modern range of A. alba, with the model exceeding the present distribution in north-western and southern Europe. Mid-Holocene pollen data and model results agree for southern Europe, suggesting that at present, human impacts suppress the distribution in southern Europe. Pollen and model results both show range expansion starting during the Bølling-Allerød warm period, interrupted by the Younger Dryas cold, and resuming during the Holocene. The distribution of A. alba expands to the north-east in all future scenarios, whereas the potential (currently unrealized) range would be substantially reduced in southern Europe under RCP8.5. A. alba maintains its current range in central Europe despite competition by other thermophilous tree species. Our combined palaeoecological and model evidence suggest that A. alba may ensure important ecosystem services including stand and slope stability, infrastructure protection, and carbon sequestration under significantly warmer

  12. Estimating Light Use Efficiency Of A Pine And Beech Forest From Leaf To Ecosystem Scale Using The Photochemical Reflectance Index

    NASA Astrophysics Data System (ADS)

    Vanikiotis, Theofilos; Markos, Nikos; Stagakis, Stavros; Tzotsos, Angelos; Sykioti, Olga; Kyparissis, Aris

    2013-12-01

    The prospect of accurately tracking photosynthetic processes using satellite observations is very important for understanding and monitoring global carbon cycle and climate change. The present study investigates the efficiency of the Photochemical Reflectance Index (PRI) in detecting light use efficiency (ɛ) in different spatial scales. The study sites concern two dense and homogenous forests in the region of Epirus (Greece), one evergreen coniferous forest dominated by Pinus nigra species and one deciduous forest dominated by Fagus sylvatica. Field and laboratory measurements of canopy structure (Leaf Area Index - LAI, needle and shoot structure characteristics), leaf pigment concentrations, leaf photosynthesis and water potential were performed throughout the growth period. These measurements were used for an accurate description of the ecophysiological characteristics of the two species and thus the parameterization of a Canopy Photosynthesis Model in order to estimate canopy photosynthesis. During the same period, leaf and canopy reflectance measurements were performed in the field to test and evaluate PRI regarding it's efficiency to track ɛ in leaf and canopy scale. In order to investigate the potential application of PRI for estimating ɛ in a broader spatial scale, satellite hyperspectral or superspectral sensors can be used. Compact High Resolution Imaging Spectrometer (CHRIS) and Moderate Resolution Imaging Spectroradiometer (MODIS) are currently available for this purpose and their performances were tested within the present study. An agreement between the fluctuations of CHRIS PRI and the field measured canopy PRI has been found, with both of them appearing to track the ɛ fluctuation efficiently. However, MODIS PRI shows no intense fluctuation and no relationship with ɛ and field measured PRI, probably due to lack of atmospheric correction and the effects of viewing and illumination geometry.

  13. Vegetation and environmental responses to climate forcing during the Last Glacial Maximum and deglaciation in the East Carpathians: attenuated response to maximum cooling and increased biomass burning

    NASA Astrophysics Data System (ADS)

    Magyari, E. K.; Veres, D.; Wennrich, V.; Wagner, B.; Braun, M.; Jakab, G.; Karátson, D.; Pál, Z.; Ferenczy, Gy; St-Onge, G.; Rethemeyer, J.; Francois, J.-P.; von Reumont, F.; Schäbitz, F.

    2014-12-01

    The Carpathian Mountains were one of the main mountain reserves of the boreal and cool temperate flora during the Last Glacial Maximum (LGM) in East-Central Europe. Previous studies demonstrated Lateglacial vegetation dynamics in this area; however, our knowledge on the LGM vegetation composition is very limited due to the scarcity of suitable sedimentary archives. Here we present a new record of vegetation, fire and lacustrine sedimentation from the youngest volcanic crater of the Carpathians (Lake St Anne, Lacul Sfânta Ana, Szent-Anna-tó) to examine environmental change in this region during the LGM and the subsequent deglaciation. Our record indicates the persistence of boreal forest steppe vegetation (with Pinus, Betula, Salix, Populus and Picea) in the foreland and low mountain zone of the East Carpathians and Juniperus shrubland at higher elevation. We demonstrate attenuated response of the regional vegetation to maximum global cooling. Between ˜22,870 and 19,150 cal yr BP we find increased regional biomass burning that is antagonistic with the global trend. Increased regional fire activity suggests extreme continentality likely with relatively warm and dry summers. We also demonstrate xerophytic steppe expansion directly after the LGM, from ˜19,150 cal yr BP, and regional increase in boreal woodland cover with Pinus and Betula from 16,300 cal yr BP. Plant macrofossils indicate local (950 m a.s.l.) establishment of Betula nana and Betula pubescens at 15,150 cal yr BP, Pinus sylvestris at 14,700 cal yr BP and Larix decidua at 12,870 cal yr BP. Pollen data furthermore support population genetic inferences regarding the regional presence of some temperate deciduous trees during the LGM (Fagus sylvatica, Corylus avellana, Fraxinus excelsior). Our sedimentological data also demonstrate intensified aeolian dust accumulation between 26,000 and 20,000 cal yr BP.

  14. Ecology of coarse wood decomposition by the saprotrophic fungus Fomes fomentarius.

    PubMed

    Větrovský, Tomáš; Voříšková, Jana; Snajdr, Jaroslav; Gabriel, Jiří; Baldrian, Petr

    2011-07-01

    Saprotrophic wood-inhabiting basidiomycetes are the most important decomposers of lignin and cellulose in dead wood and as such they attracted considerable attention. The aims of this work were to quantify the activity and spatial distribution of extracellular enzymes in coarse wood colonised by the white-rot basidiomycete Fomes fomentarius and in adjacent fruitbodies of the fungus and to analyse the diversity of the fungal and bacterial community in a fungus-colonised wood and its potential effect on enzyme production by F. fomentarius. Fungus-colonised wood and fruitbodies were collected in low management intensity forests in the Czech Republic. There were significant differences in enzyme production by F. fomentarius between Betula pendula and Fagus sylvatica wood, the activity of cellulose and xylan-degrading enzymes was significantly higher in beech wood than in birch wood. Spatial analysis of a sample B. pendula log segment proved that F. fomentarius was the single fungal representative found in the log. There was a high level of spatial variability in the amount of fungal biomass detected, but no effects on enzyme activities were observed. Samples from the fruiting body showed high β-glucosidase and chitinase activities compared to wood samples. Significantly higher levels of xylanase and cellobiohydrolase were found in samples located near the fruitbody (proximal), and higher laccase and Mn-peroxidase activities were found in the distal ones. The microbial community in wood was dominated by the fungus (fungal to bacterial DNA ratio of 62-111). Bacterial abundance composition was lower in proximal than distal parts of wood by a factor of 24. These results show a significant level of spatial heterogeneity in coarse wood. One of the explanations may be the successive colonization of wood by the fungus: due to differential enzyme production, the rates of biodegradation of coarse wood are also spatially inhomogeneous.

  15. Combining stable isotope and carbohydrate analyses in phloem sap and fine roots to study seasonal changes of source-sink relationships in a Mediterranean beech forest.

    PubMed

    Scartazza, Andrea; Moscatello, Stefano; Matteucci, Giorgio; Battistelli, Alberto; Brugnoli, Enrico

    2015-08-01

    Carbon isotope composition (δ(13)C) and carbohydrate content of phloem sap and fine roots were measured in a Mediterranean beech (Fagus sylvatica L.) forest throughout the growing season to study seasonal changes of source-sink relationships. Seasonal variations of δ(13)C and content of phloem sap sugars, collected during the daylight period, reflected the changes in soil and plant water status. The correlation between δ(13)C and content of phloem sap sugars, collected from plants belonging to different social classes, was significantly positive only during the driest month of July. In this month, δ(13)C of phloem sap sugars was inversely related to the increment of trunk radial growth and positively related to δ(13)C of fine roots. We conclude that the relationship between δ(13)C and the amount of phloem sap sugars is affected by a combination of causes, such as sink strength, tree social class, changes in phloem anatomy and transport capacity, and phloem loading of sugars to restore sieve tube turgor following the reduced plant water potential under drought conditions. However, δ(13)C and sugar composition of fine roots suggested that phloem transport of leaf sucrose to this belowground component was not impaired by mild drought and that sucrose was in a large part allocated towards fine roots in July, depending on tree social class. Hence, fine roots could represent a functional carbon sink during the dry seasonal periods, when transport and use of assimilates in other sink tissues are reduced. These results indicate a strict link between above- and belowground processes and highlight a rapid response of this Mediterranean forest to changes in environmental drivers to regulate source-sink relationships and carbon sink capacity.

  16. Stomatal and pavement cell density linked to leaf internal CO2 concentration

    PubMed Central

    Šantrůček, Jiří; Vráblová, Martina; Šimková, Marie; Hronková, Marie; Drtinová, Martina; Květoň, Jiří; Vrábl, Daniel; Kubásek, Jiří; Macková, Jana; Wiesnerová, Dana; Neuwithová, Jitka; Schreiber, Lukas

    2014-01-01

    Background and Aims Stomatal density (SD) generally decreases with rising atmospheric CO2 concentration, Ca. However, SD is also affected by light, air humidity and drought, all under systemic signalling from older leaves. This makes our understanding of how Ca controls SD incomplete. This study tested the hypotheses that SD is affected by the internal CO2 concentration of the leaf, Ci, rather than Ca, and that cotyledons, as the first plant assimilation organs, lack the systemic signal. Methods Sunflower (Helianthus annuus), beech (Fagus sylvatica), arabidopsis (Arabidopsis thaliana) and garden cress (Lepidium sativum) were grown under contrasting environmental conditions that affected Ci while Ca was kept constant. The SD, pavement cell density (PCD) and stomatal index (SI) responses to Ci in cotyledons and the first leaves of garden cress were compared. 13C abundance (δ13C) in leaf dry matter was used to estimate the effective Ci during leaf development. The SD was estimated from leaf imprints. Key Results SD correlated negatively with Ci in leaves of all four species and under three different treatments (irradiance, abscisic acid and osmotic stress). PCD in arabidopsis and garden cress responded similarly, so that SI was largely unaffected. However, SD and PCD of cotyledons were insensitive to Ci, indicating an essential role for systemic signalling. Conclusions It is proposed that Ci or a Ci-linked factor plays an important role in modulating SD and PCD during epidermis development and leaf expansion. The absence of a Ci–SD relationship in the cotyledons of garden cress indicates the key role of lower-insertion CO2 assimilation organs in signal perception and its long-distance transport. PMID:24825295

  17. Strong Coupling of Shoot Assimilation and Soil Respiration during Drought and Recovery Periods in Beech As Indicated by Natural Abundance δ(13)C Measurements.

    PubMed

    Blessing, Carola H; Barthel, Matti; Gentsch, Lydia; Buchmann, Nina

    2016-01-01

    Drought down-regulates above- and belowground carbon fluxes, however, the resilience of trees to drought will also depend on the speed and magnitude of recovery of these above- and belowground fluxes after re-wetting. Carbon isotope composition of above- and belowground carbon fluxes at natural abundance provides a methodological approach to study the coupling between photosynthesis and soil respiration (SR) under conditions (such as drought) that influence photosynthetic carbon isotope discrimination. In turn, the direct supply of root respiration with recent photoassimilates will impact on the carbon isotope composition of soil-respired CO2. We independently measured shoot and soil CO2 fluxes of beech saplings (Fagus sylvatica L.) and their respective δ(13)C continuously with laser spectroscopy at natural abundance. We quantified the speed of recovery of drought stressed trees after re-watering and traced photosynthetic carbon isotope signal in the carbon isotope composition of soil-respired CO2. Stomatal conductance responded strongly to the moderate drought (-65%), induced by reduced soil moisture content as well as increased vapor pressure deficit. Simultaneously, carbon isotope discrimination decreased by 8‰, which in turn caused a significant increase in δ(13)C of recent metabolites (1.5-2.5‰) and in δ(13)C of SR (1-1.5‰). Generally, shoot and soil CO2 fluxes and their δ(13)C were in alignment during drought and subsequent stress release, clearly demonstrating a permanent dependence of root respiration on recently fixed photoassimilates, rather than on older reserves. After re-watering, the drought signal persisted longer in δ(13)C of the water soluble fraction that integrates multiple metabolites (soluble sugars, amino acids, organic acids) than in the neutral fraction which represents most recently assimilated sugars or in the δ(13)C of SR. Nevertheless, full recovery of all aboveground physiological variables was reached within 4 days - and

  18. Vegetation of the selected forest stands and land use in the Carpathian Mountains.

    PubMed

    Grodzińska, Krystyna; Godzik, Barbara; Fraczek, Witold; Badea, Ovidiu; Oszlányi, Július; Postelnicu, Daniela; Shparyk, Yuriy

    2004-07-01

    Within the framework of the project "Effects of forest health on biodiversity with emphasis on air pollution in the Carpathian Mountains" 26 permanent study sites were established in the vicinity of the ozone monitoring sites. The study sites were located on the NW-SE transect through the Western (12 sites), Eastern (11 sites) and Southern (3 sites) Carpathians in forest ecosystems typical of each area. Some of the forest monitoring sites were located in national parks, biosphere reserves and areas of protected landscape. Each permanent site of 0.7 ha area consisted of 5 small 500m(2) circular plots, arranged in the form of a cross, i.e. four placed on the cardinal points (N, E, S, W) and one in the center. Phytosociological records were done twice during the 1998 growing season using the Braun-Blanquet's method. The study sites represented various types of forest: Picea abies stands (8), beech (Fagus sylvatica) stands (10), fir (Abies alba) stands (2) and mixed beech-fir, spruce-fir and beech-spruce stands (6). Age of most stands was 80-100 years. Degree of crown damage varied greatly between sites, a percentage of damaged trees decrease in Carpathians from West to East. It corresponds well with the O(3) level in these areas. Typical damage by O(3) in herb layer species in several Carpathian sites were found. Land-use map for the entire Carpathian Mountains and two detailed land use maps for Tatras (Western Carpathians) and Retezat (Southern Carpathians) are presented. A little more than half of the Carpathian territory is forested. The most densely forested are Eastern Carpathians, while the most sparsely Western Carpathians. Arable lands occupy 22.6% of the Carpathians, pastures and meadows 6.2%, water bodies 1.9%, and build up areas several percent. In the highest elevation of the Carpathians alpine meadows (11.3%) and rocks (3.5%) are distributed.

  19. Effects of ozone on ecosystems -- ecosystem indicators of concern

    SciTech Connect

    Innes, J.L.

    1998-12-31

    Ozone has been recognized as an important cause of damage to crops since the 1950s. Damage to trees was first identified in the 1960s and is now known to be widespread in both North America and Europe. Most impact studies have emphasized the importance of determining growth losses attributable to ozone and as a result have concentrated on species of commercial importance. This is illustrated by the critical loads approach to ozone risk assessment in Europe, which is currently based on the AOT40 -- 10 ppmh threshold. At higher levels, it has been argued that a 10% growth reduction occurs in European beech (Fagus sylvatica). Such an approach suffers from a number of serious limitations, not least the widespread impacts on ecosystems that may occur at lower ozone exposures and the very poor quantitative basis for setting this threshold. In Europe, there has been increasing emphasis on the conservation and management of species without any direct economic importance. This has arisen from a growing environmental awareness of the general public. The trend has been accelerated by the perceived environmental benefits of the large amounts of land that has been taken out of agricultural production (as a result of the ``set-aside`` policy of the European Union) and the public concern about the ecological and environmental impacts of industrial forestry. In agricultural landscapes, hedgerow species and weed species are being looked at as important parts of the agricultural ecosystem. In particular, weed species are an important part of the food chain for the wildlife present in such ecosystems. In forests, much greater emphasis is being given to the authenticity of the forest ecosystems. Particular emphasis is being given to ecosystem management techniques such as continuous cover forestry and the furthering of natural regeneration.

  20. Calcaridorylaimus castaneae sp. n. (Nematoda, Dorylaimidae) from Bulgaria with an identification key to the species of the genus

    PubMed Central

    Nedelchev, Sevdan; Elshishka, Milka; Lazarova, Stela; Radoslavov, Georgi; Hristov, Peter; Peneva, Vlada

    2014-01-01

    Abstract An unknown species belonging to the genusCalcaridorylaimus Andrássy, 1986 was collected from the litter of broadleaf forests dominated by Castanea sativa Mill. and mixed with Quercus daleshampii Ten. and Fagus sylvatica L. on Belasitsa Mountain, south-western Bulgaria. Calcaridorylaimus castaneae sp. n. is characterised by its long body (1.4–2.1 mm), lip region practically not offset, vulva transverse, short odontostyle (14.5–16 μm) and tail (75.5–110.5 μm, c=14.7–23.6; c’=2.9–4.4) in females and 38–46 μm long spicules with small spur before their distant end in males. It is most similar to C. andrassyi Ahmad & Shaheen, 2004, but differs in having transverse vs pore-like vulva and shorter spicules (38–46 μm vs 52–57 μm). An identification key to the species of the genus Calcaridorylaimus is proposed. Phylogenetic analyses were performed on 18S and D2-D3 expansion domains of 28S rRNA genes by Neighbor-Joining, Maximum Likelihood and Bayesian Inference methods. The phylograms inferred from 18S sequences showed closest relationships of the new species with some species belonging to the genus Mesodorylaimus. However, insufficient molecular data for members of both genera do not allow the phylogenetic relationships of Calcaridorylaimus and the new species described herein to be elucidated. PMID:24899849

  1. Dominant controls of transpiration along a hillslope transect inferred from ecohydrological measurements and thermodynamic limits

    NASA Astrophysics Data System (ADS)

    Renner, Maik; Hassler, Sibylle K.; Blume, Theresa; Weiler, Markus; Hildebrandt, Anke; Guderle, Marcus; Schymanski, Stanislaus J.; Kleidon, Axel

    2016-05-01

    We combine ecohydrological observations of sap flow and soil moisture with thermodynamically constrained estimates of atmospheric evaporative demand to infer the dominant controls of forest transpiration in complex terrain. We hypothesize that daily variations in transpiration are dominated by variations in atmospheric demand, while site-specific controls, including limiting soil moisture, act on longer timescales. We test these hypotheses with data of a measurement setup consisting of five sites along a valley cross section in Luxembourg. Both hillslopes are covered by forest dominated by European beech (Fagus sylvatica L.). Two independent measurements are used to estimate stand transpiration: (i) sap flow and (ii) diurnal variations in soil moisture, which were used to estimate the daily root water uptake. Atmospheric evaporative demand is estimated through thermodynamically constrained evaporation, which only requires absorbed solar radiation and temperature as input data without any empirical parameters. Both transpiration estimates are strongly correlated to atmospheric demand at the daily timescale. We find that neither vapor pressure deficit nor wind speed add to the explained variance, supporting the idea that they are dependent variables on land-atmosphere exchange and the surface energy budget. Estimated stand transpiration was in a similar range at the north-facing and the south-facing hillslopes despite the different aspect and the largely different stand composition. We identified an inverse relationship between sap flux density and the site-average sapwood area per tree as estimated by the site forest inventories. This suggests that tree hydraulic adaptation can compensate for heterogeneous conditions. However, during dry summer periods differences in topographic factors and stand structure can cause spatially variable transpiration rates. We conclude that absorption of solar radiation at the surface forms a dominant control for turbulent heat and

  2. Metaproteome analysis of the microbial community during leaf litter decomposition - the impact of stoichiometry and temperature perturbations

    NASA Astrophysics Data System (ADS)

    Keiblinger, K. M.; Schneider, T.; Leitner, S.; Hämmerle, I.; Riedel, K.; Zechmeister-Boltenstern, S.

    2012-04-01

    Leaf litter decomposition is the breakdown of dead plant material, a terrestrial ecosystem process of paramount importance. Nutrients released during decomposition play a key role for microbial growth and plant productivity. These processes are controlled by abiotic factors, such as climate, and by biotic factors, such as litter nutrient concentration and stoichiometry (carbon:nutrient ratio) and activity of soil organisms. Future climate change scenarios predict temperature perturbations, therefore following changes of microbial community composition and possible feedbacks on ecosystem processes are of key interest; especially as our knowledge about the microbial regulation of these processes is still scarce. Our aim was to elucidate how temperature perturbations and leaf litter stoichiometry affect the composition of the microbial decomposer community. To this end a terrestrial microcosm experiment using beech (Fagus sylvatica) litter with different stoichiometry was conducted. In a semi-quantitative metaproteomics approach (1D-SDS PAGE combined with liquid chromatography and tandem mass spectrometry; unique spectral counting) we used the intrinsic metabolic function of proteins to relate specific microbial activities to their phylogenetic origin in multispecies communities. Decomposer communities varied on litter with different stoichiometry so that microbial decomposers (fungi and bacteria) were favoured in litter with narrow C:nutrient ratios. The fungal community was dominated by Ascomycota (Eurotiomycetes, Sordariomycetes) and Basidiomycota (Agaricomycetes) and the bacterial community was dominated by Proteobacteria, Actinobacteria and Firmicutes. The extracellular enzymes we detected belonged mainly to classes of xylanases, pectinases, cellulases and proteases and were almost exclusively of fungal origin (particularly Ascomycota). Temperature stress (heat and frost) evoked strong changes in community composition, enzyme activities, dissolved organic

  3. Using Sex Pheromone and a Multi-Scale Approach to Predict the Distribution of a Rare Saproxylic Beetle

    PubMed Central

    Musa, Najihah; Andersson, Klas; Burman, Joseph; Andersson, Fredrik; Hedenström, Erik; Jansson, Nicklas; Paltto, Heidi; Westerberg, Lars; Winde, Inis; Larsson, Mattias C.; Bergman, Karl-Olof; Milberg, Per

    2013-01-01

    The European red click beetle, Elater ferrugineus L., is associated with wood mould in old hollow deciduous trees. As a result of severe habitat fragmentation caused by human disturbance, it is threatened throughout its distribution range. A new pheromone-based survey method, which is very efficient in detecting the species, was used in the present study to relate the occurrence of E. ferrugineus to the density of deciduous trees. The latter data were from a recently completed regional survey in SE Sweden recording >120,000 deciduous trees. The occurrence of E. ferrugineus increased with increasing amount of large hollow and large non-hollow trees in the surrounding landscape. Quercus robur (oak) was found to be the most important substrate for E. ferrugineus, whereas two groups of tree species (Carpinus betulus, Fagus sylvatica, Ulmus glabra, vs. Acer platanoides, Aesculus hippocastanum, Fraxinus excelsior, Tilia cordata) were less important but may be a complement to oak in sustaining populations of the beetle. The occurrence of E. ferrugineus was explained by the density of oaks at two different spatial scales, within the circle radii 327 m and 4658 m. In conclusion, priority should be given to oaks in conservation management of E. ferrugineus, and then to the deciduous trees in the genera listed above. Conservation planning at large spatial and temporal scales appears to be essential for long-term persistence of E. ferrugineus. We also show that occurrence models based on strategic sampling might result in pessimistic predictions. This study demonstrates how pheromone-based monitoring make insects excellent tools for sustained feedback to models for landscape conservation management. PMID:23840415

  4. Intra-specific variations in expression of stress-related genes in beech progenies are stronger than drought-induced responses.

    PubMed

    Carsjens, Caroline; Nguyen Ngoc, Quynh; Guzy, Jonas; Knutzen, Florian; Meier, Ina Christin; Müller, Markus; Finkeldey, Reiner; Leuschner, Christoph; Polle, Andrea

    2014-12-01

    Rapidly decreasing water availability as a consequence of climate change is likely to endanger the range of long-lived tree species. A pressing question is, therefore, whether adaptation to drought exists in important temperate tree species like European beech (Fagus sylvatica L.), a wide-spread, dominant forest tree in Central Europe. Here, five beech stands were selected along a precipitation gradient from moist to dry conditions. Neutral genetic markers revealed strong variation within and little differentiation between the populations. Natural regeneration from these stands was transferred to a common garden and used to investigate the expression of genes for abscisic acid (ABA)-related drought signaling [9-cis-epoxy-dioxygenase (NCED), protein phosphatase 2C (PP2C), early responsive to dehydration (ERD)] and stress protection [ascorbate peroxidase (APX), superoxide dismutase (SOD), aldehyde dehydrogenase (ALDH), glutamine amidotransferase (GAT)] that are involved in drought acclimation. We hypothesized that progenies from dry sites exhibit constitutively higher expression levels of ABA- and stress-related genes and are less drought responsive than progenies from moist sites. Transcript levels and stress responses (leaf area loss, membrane integrity) of well-irrigated and drought-stressed plants were measured during the early, mid- and late growing season. Principal component (PC) analysis ordered the beech progenies according to the mean annual precipitation at tree origin by the transcript levels of SOD, ALDH, GAT and ERD as major loadings along PC1. PC2 separated moist and drought treatments with PP2C levels as important loading. These results suggest that phosphatase-mediated signaling is flexibly acclimated to the current requirements, whereas stress compensatory measures exhibited genotypic variation, apparently underlying climate selection. In contrast to expectation, the drought responses were less pronounced than the progeny-related differences and the

  5. A highly spatially resolved GIS-based model to assess the isoprenoid emissions from key Italian ecosystems

    NASA Astrophysics Data System (ADS)

    Pacheco, Claudia Kemper; Fares, Silvano; Ciccioli, Paolo

    2014-10-01

    The amount of Biogenic Volatile Organic Compounds (BVOC) emitted from terrestrial vegetation is of great importance in atmospheric reactivity, particularly for ozone-forming reactions and as condensation nuclei in aerosol formation and growth. This work presents a detailed inventory of isoprenoid emissions from vegetation in Italy using an original approach which combines state of the art models to estimate the species-specific isoprenoid emissions and a Geographic Information System (GIS) where emissions are spatially represented. Isoprenoid species and basal emission factors were obtained by combining results from laboratory experiments with those published in literature. For the first time, our investigation was not only restricted to isoprene and total monoterpenes, but our goal was to provide maps of isoprene and individual monoterpenes at a high-spatial (˜1 km2) and temporal resolution (daily runs, monthly trends in emissions are discussed in the text). Another novelty in our research was the inclusion of the effects of phenology on plant emissions. Our results show that: a) isoprene, a-pinene, sabinene and b-pinene are the most important compounds emitted from vegetation in Italy; b) annual biogenic isoprene and monoterpene fluxes for the year 2006 were ˜31.30 Gg and ˜37.70 Gg, respectively; and c) Quercus pubescens + Quercus petrea + Quercus robur, Quercus ilex, Quercus suber and Fagus sylvatica are the principal isoprenoid emitting species in the country. The high spatial and temporal resolution, combined with the species-specific emission output, makes the model particularly suitable for assessing local budgets, and for modeling photochemical pollution in Italy.

  6. Assessing the role of soil water limitation in determining the Phytotoxic Ozone Dose (PODY) thresholds

    NASA Astrophysics Data System (ADS)

    De Marco, Alessandra; Sicard, Pierre; Fares, Silvano; Tuovinen, Juha-Pekka; Anav, Alessandro; Paoletti, Elena

    2016-12-01

    Phytotoxic Ozone Dose (PODY), defined as the accumulated stomatal ozone flux over a threshold of Y, is considered an optimal metric to evaluate O3 effects on vegetation. PODY is often computed through the DO3SE model, which includes species-specific parameterizations for the environmental response of stomatal conductance. However, the effect of soil water content (SWC) on stomatal aperture is difficult to model on a regional scale and thus often ignored. In this study, we used environmental input data obtained from the WRF-CHIMERE model for 14,546 grid-based forest sites in Southern Europe. SWC was obtained for the upper 10 cm of soil, which resulted in a worst-case risk scenario. PODY was calculated either with or without water limitation for different Y thresholds. Exclusion of the SWC effect on stomatal fluxes caused a serious overestimation of PODY. The difference increased with increasing Y (78%, 128%, 237% and 565% with Y = 0, 1, 2 and 3 nmol O3 m-2 s-1, respectively). This behaviour was confirmed by applying the same approach to field data measured in a Mediterranean Quercus ilex forest. WRF-CHIMERE overestimated SWC at this field site, so under real-world conditions the SWC effect may be larger than modelled. The differences were lower for temperate species (Pinus cembra 50-340%, P. sylvestris 57-363%, Abies alba 57-371%) than for Mediterranean species (P. pinaster 87-356%, P. halepensis 96-429%, P. pinea 107-532%, Q. suber 104-1602%), although a high difference was recorded also for the temperate species Fagus sylvatica with POD3 (524%). We conclude that SWC should be considered in PODY simulations and a low Y threshold should be used for robustness.

  7. Explaining the variability of the photochemical reflectance index (PRI) at the canopy-scale: Disentangling the effects of phenological and physiological changes.

    PubMed

    Merlier, Elodie; Hmimina, Gabriel; Dufrêne, Eric; Soudani, Kamel

    2015-10-01

    Assessing photosynthesis rates at the ecosystem scale and over large regions is important for tracking the global carbon cycle and remote sensing has provided new and useful approaches for performing this assessment. The photochemical reflectance index (PRI) is a good estimator of short-term light-use efficiency (LUE) at the leaf scale; however, confounding factors appear at larger temporal and spatial scales. In this study, canopy-scale PRI variability was investigated for three species (Fagus sylvatica L., Quercus robur L. and Pinus sylvestris L.) growing under contrasting soil moisture conditions. Throughout the growing season, no significant differences in chlorophyll content and in violaxanthin, antheraxanthin and zeaxanthin were found between species or treatments. The daily PRI vs PAR (photosynthetically active radiation) relationships were determined using continuous measurements obtained at high frequency throughout the entire growing season, from early spring budburst to later autumn senescence, and were used to deconvolute the physiological PRI variability related to LUE variations due to phenological variability and related to temporal changes in the biochemical and structural canopy attributes. The PRI vs PAR relationship is used to show that the canopy-scale PRI measured at low radiation depends on the chlorophyll content of the canopy. The range of PRI variations at an intra-daily scale and the dynamics of the xanthophyll pool do not vary between days, which suggests that the PRI responds to a xanthophyll ratio. The PAR values at PRI saturation are mainly related to the canopy chlorophyll content during budburst and senescence and to the soil moisture content when the chlorophyll content is no longer a limiting factor. This parameter is significantly lower in the oak species that experience less stress from variations in soil moisture and is species dependant. These results provide new insights regarding the analysis and the meaning of PRI

  8. Morphological, biochemical and physiological traits of upper and lower canopy leaves of European beech tend to converge with increasing altitude.

    PubMed

    Rajsnerová, Petra; Klem, Karel; Holub, Petr; Novotná, Kateřina; Večeřová, Kristýna; Kozáčiková, Michaela; Rivas-Ubach, Albert; Sardans, Jordi; Marek, Michal V; Peñuelas, Josep; Urban, Otmar

    2015-01-01

    The present work has explored for the first time acclimation of upper versus lower canopy leaves along an altitudinal gradient. We tested the hypothesis that restrictive climatic conditions associated with high altitudes reduce within-canopy variations of leaf traits. The investigated beech (Fagus sylvatica L.) forest is located on the southern slope of the Hrubý Jeseník Mountains (Czech Republic). All measurements were taken on leaves from upper and lower parts of the canopy of mature trees (>85 years old) growing at low (400 m above sea level, a.s.l.), middle (720 m a.s.l.) and high (1100 m a.s.l.) altitudes. Compared with trees at higher altitudes, those growing at low altitudes had lower stomatal conductance, slightly lower CO(2) assimilation rate (A(max)) and leaf mass per area (LMA), and higher photochemical reflectance index, water-use efficiency and Rubisco content. Given similar stand densities at all altitudes, the different growth conditions result in a more open canopy and higher penetration of light into lower canopy with increasing altitude. Even though strong vertical gradients in light intensity occurred across the canopy at all altitudes, lower canopy leaves at high altitudes tended to acquire the same morphological, biochemical and physiological traits as did upper leaves. While elevation had no significant effect on nitrogen (N) and carbon (C) contents per unit leaf area, LMA, or total content of chlorophylls and epidermal flavonoids in upper leaves, these increased significantly in lower leaves at higher altitudes. The increases in N content of lower leaves were coupled with similar changes in A(max). Moreover, a high N content coincided with high Rubisco concentrations in lower but not in upper canopy leaves. Our results show that the limiting role of light in lower parts of the canopy is reduced at high altitudes. A great capacity of trees to adjust the entire canopy is thus demonstrated.

  9. Chemical and morphological characteristics of key tree species of the Carpathian Mountains.

    PubMed

    Mankovská, Blanka; Godzik, Barbara; Badea, Ovidiu; Shparyk, Yuri; Moravcík, Pavel

    2004-07-01

    Concentrations of Al, B, Ca, Cu, Fe, K, Mg, Mn, N, Na, P, S and Zn in the foliage of white fir (Abies alba), Norway spruce (Picea abies) and common beech (Fagus sylvatica) from 25 sites of the Carpathian Mts. forests (Czech Republic, Poland, Romania, Slovakia and Ukraine) are discussed in a context of their limit values. S/N ratio was different from optimum in 90% of localities when compared with the European limit values. Likewise we found increase of Fe and Cu concentrations compared with their background levels in 100% of locations. Mn concentrations were increased in 76% of localities. Mn mobilization values indicate the disturbance of physiological balance leading to the change of the ratio with Fe. SEM-investigation of foliage waxes from 25 sites in the Carpathian Mts. showed, that there is a statistically significant difference in mean wax quality. Epistomatal waxes were damaged as indicated by increased development of net and amorphous waxes. The most damaged stomata in spruce needles were from Yablunitsa, Synevir and Brenna; in fir needles from Stoliky, and in beech leaves from Malá Fatra, Morské Oko and Beregomet. Spruce needles in the Carpathian Mts. had more damaged stomata than fir needles and beech leaves. Spruce seems to be the most sensitive tree species to environmental stresses including air pollution in forests of the Carpathian Mountains. Foliage surfaces of three forest tree species contained Al, Si, Ca, Fe, Mg, K, Cl, Mn, Na, Ni and Ti in all studied localities. Presence of nutrition elements (Ca, Fe, Mg, K and Mn) on foliage surface hinders opening and closing stomata and it is not physiologically usable for tree species.

  10. Forest health status in the Carpathian Mountains over the period 1997-2001.

    PubMed

    Badea, Ovidiu; Tanase, Mihai; Georgeta, Jianu; Anisoara, Lazar; Peiov, Agata; Uhlirova, Hana; Pajtik, Josef; Wawrzoniak, Jerzy; Shparyk, Yuri

    2004-07-01

    The results of forest health status assessments in the Carpathian Mountains from the monitoring networks developed by the European Union Scheme on the Protection of Forest Against Atmospheric Pollution (EU Scheme) and International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP-Forests), have led to a better understanding of the impact of air pollution and other stressors on forests at the regional scale. During the period 1997-2001, forests in the Carpathian Mountains were severely affected by air pollution and natural stresses with 29.7-34.9% of the trees included in defoliation classes 2-4. The broadleaves were slightly healthier than the conifers, and European beech (Fagus sylvatica) was the least affected species. Norway spruce (Picea abies) has poor health status, with 42.9-46.6% of the trees damaged (2-4% defoliation classes). Silver fir (Abies alba) damage was also high, with 46.0-50.9% in defoliation classes 2-4. Pines (primarily Pinus sylvestris) were the least affected of the conifers, with 24.9-33.8% in defoliation classes 2-4. The results from the transnational networks (16 x 16 km) show that the Carpathian forests are slightly more damaged than the average for the entire Europe. The correlative studies performed in individual European countries show the relationships between air pollution stressors with trends in defoliation and a possible effect of natural stresses at each site. More specific, effects of tree age, drought, ozone and acid deposition critical level exceedances were demonstrated to affect crown condition.

  11. Influence of fine-scale habitat structure on nest-site occupancy, laying date and clutch size in Blue Tits Cyanistes caeruleus

    NASA Astrophysics Data System (ADS)

    Amininasab, Seyed Mehdi; Vedder, Oscar; Schut, Elske; de Jong, Berber; Magrath, Michael J. L.; Korsten, Peter; Komdeur, Jan

    2016-01-01

    Most birds have specific habitat requirements for breeding. The vegetation structure surrounding nest-sites is an important component of habitat quality, and can have large effects on avian breeding performance. We studied 13 years of Blue Tit Cyanistes caeruleus population data to determine whether characteristics of vegetation structure predict site occupancy, laying date and number of eggs laid. Measurements of vegetation structure included the density of English Oak Quercus robur, European Beech Fagus sylvatica, and other deciduous, coniferous and non-coniferous evergreen trees, within a 20-m radius of nest-boxes used for breeding. Trees were further sub-divided into specific classes of trunk circumferences to determine the densities for different maturity levels. Based on Principal Component Analysis (PCA), we reduced the total number of 17 measured vegetation variables to 7 main categories, which we used for further analyses. We found that the occupancy rate of sites and the number of eggs laid correlated positively with the proportion of deciduous trees and negatively with the density of coniferous trees. Laying of the first egg was advanced with a greater proportion of deciduous trees. Among deciduous trees, the English Oak appeared to be most important, as a higher density of more mature English Oak trees was associated with more frequent nest-box occupancy, a larger number of eggs laid, and an earlier laying start. Furthermore, laying started earlier and more eggs were laid in nest-boxes with higher occupancy rates. Together, these findings highlight the role of deciduous trees, particularly more mature English Oak, as important predictors of high-quality preferred habitat. These results aid in defining habitat quality and will facilitate future studies on the importance of environmental quality for breeding performance.

  12. Effects of ring-porous and diffuse-porous stem wood anatomy on the hydraulic parameters used in a water flow and storage model.

    PubMed

    Steppe, Kathy; Lemeur, Raoul

    2007-01-01

    Calibration of a recently developed water flow and storage model based on experimental data for a young diffuse-porous beech tree (Fagus sylvatica L.) and a young ring-porous oak tree (Quercus robur L.) revealed that differences in stem wood anatomy between species strongly affect the calibrated values of the hydraulic model parameters. The hydraulic capacitance (C) of the stem storage tissue was higher in oak than in beech (939.8 versus 212.3 mg MPa(-1)). Model simulation of the elastic modulus (epsilon) revealed that this difference was linked to the higher elasticity of the stem storage tissue of oak compared with beech. Furthermore, the hydraulic resistance (R (x)) of beech was about twice that of oak (0.1829 versus 0.1072 MPa s mg(-1)). To determine the physiological meaning of the R (x) parameter identified by model calibration, we analyzed the stem wood anatomy of the beech and oak trees. Calculation of stem specific hydraulic conductivity (k (s)) of beech and oak with the Hagen-Poiseuille equation confirmed the differences in R (x) predicted by the model. The contributions of different vessel diameter classes to the total hydraulic conductivity of the xylem were calculated. As expected, the few big vessels contributed much more to total conductivity than the many small vessels. Compared with beech, the larger vessels of oak resulted in a higher k (s) (10.66 versus 4.90 kg m(-1) s(-1) MPa(-1)). The calculated ratio of k (s) of oak to beech was 2, confirming the R (x) ratio obtained by model calibration. Thus, validation of the R (x) parameter of the model led to identification of its physiological meaning.

  13. Evaluation of morphological and chemical aspects of different wood species by spectroscopy and thermal methods

    NASA Astrophysics Data System (ADS)

    Popescu, Maria-Cristina; Popescu, Carmen-Mihaela; Lisa, Gabriela; Sakata, Yusaku

    2011-03-01

    The aim of this study is to find the most convenient procedure to make an easy differentiation between various kinds of wood. The wood samples used were: fir (Acer alba), poplar (Populus tremula), lime (Tillia cordata), sycamore (Acer pseudoplatanus), sweet cherry (Prunus avium), hornbeam (Carpinus betulus), walnut (Juglans regia), beech (Fagus sylvatica), oak (Quercus robur). The methods of investigation used were FT-IR spectroscopy, X-ray diffraction and thermogravimetry. By FT-IR spectroscopy, was observed that the ratio values of lignin/carbohydrate IR bands for wood decreases with increasing the average wood density, showing a decrease in lignin content. Also, the calculated values of lignin percentage from the FT-IR spectra are in very good correlation with the values from literature. Following the deconvolution process of the X-ray diffraction patterns, it was found that the degree of crystallinity, the apparent lateral crystallite size, the proportion of crystallite interior chains and cellulose fraction tend to increase with increasing of the wood density. Thermal analysis is able to give information about degradation temperatures for the principal components of different wood samples. The shape of DTG curves depends on the wood species that cause the enlargement of the peaks or the maxima of the decomposition step varies at larger or smaller temperatures ranges. The temperatures and weight loss percentage are particular for each kind of wood. This study showed that analytical methods used have the potential to be important sources of information for a quick evaluation of the chemical composition of wood samples.

  14. Impacts of age-dependent tree sensitivity and dating approaches on dendrogeomorphic time series of landslides

    NASA Astrophysics Data System (ADS)

    Šilhán, Karel; Stoffel, Markus

    2015-05-01

    Different approaches and thresholds have been utilized in the past to date landslides with growth ring series of disturbed trees. Past work was mostly based on conifer species because of their well-defined ring boundaries and the easy identification of compression wood after stem tilting. More recently, work has been expanded to include broad-leaved trees, which are thought to produce less and less evident reactions after landsliding. This contribution reviews recent progress made in dendrogeomorphic landslide analysis and introduces a new approach in which landslides are dated via ring eccentricity formed after tilting. We compare results of this new and the more conventional approaches. In addition, the paper also addresses tree sensitivity to landslide disturbance as a function of tree age and trunk diameter using 119 common beech (Fagus sylvatica L.) and 39 Crimean pine (Pinus nigra ssp. pallasiana) trees growing on two landslide bodies. The landslide events reconstructed with the classical approach (reaction wood) also appear as events in the eccentricity analysis, but the inclusion of eccentricity clearly allowed for more (162%) landslides to be detected in the tree-ring series. With respect to tree sensitivity, conifers and broad-leaved trees show the strongest reactions to landslides at ages comprised between 40 and 60 years, with a second phase of increased sensitivity in P. nigra at ages of ca. 120-130 years. These phases of highest sensitivities correspond with trunk diameters at breast height of 6-8 and 18-22 cm, respectively (P. nigra). This study thus calls for the inclusion of eccentricity analyses in future landslide reconstructions as well as for the selection of trees belonging to different age and diameter classes to allow for a well-balanced and more complete reconstruction of past events.

  15. An empirical study of the wound effect on sap flux density measured with thermal dissipation probes.

    PubMed

    Wiedemann, Andreas; Marañón-Jiménez, Sara; Rebmann, Corinna; Herbst, Mathias; Cuntz, Matthias

    2016-12-01

    The insertion of thermal dissipation (TD) sensors on tree stems for sap flux density (SFD) measurements can lead to SFD underestimations due to a wound formation close to the drill hole. However, the wound effect has not been assessed experimentally for this method yet. Here, we propose an empirical approach to investigate the effect of the wound healing on measured sap flux with TD probes. The approach was performed for both, diffuse-porous (Fagus sylvatica (Linnaeus)) and ring-porous (Quercus petraea (Lieblein)) species. Thermal dissipation probes were installed on different dates along the growing season to document the effects of the dynamic wound formation. The trees were cut in autumn and additional sensors were installed in the cut stems, therefore, without potential effects of wound development. A range of water pressures was applied to the stem segments and SFDs were simultaneously measured by TD sensors as well as gravimetrically in the laboratory. The formation of wounds around sensors installed in living tree stems led to underestimation of SFD by 21.4 ± 3 and 47.5 ± 3.8% in beech and oak, respectively. The differences between SFD underestimations of diffuse-porous beech and ring-porous oak were, however, not statistically significant. Sensors with 5-, 11- and 22-week-old wounds also showed no significant differences, which implies that the influence of wound formation on SFD estimates was completed within the first few weeks after perforation. These results were confirmed by time courses of SFD measurements in the field. Field SFD values decreased immediately after sensor installation and reached stable values after ~2 weeks with similar underestimations to the ones observed in the laboratory. We therefore propose a feasible approach to correct directly field observations of SFD for potential underestimations due to the wound effect.

  16. Release and retention patterns of organic compounds and nutrients after the cold period in foliar litterfall of pure European larch, common beech and red oak plantations in Lithuania

    NASA Astrophysics Data System (ADS)

    Čiuldienė, D.; Aleinikovienė, J.; Muraškienė, M.; Marozas, V.; Armolaitis, K.

    2017-01-01

    This study was carried out in alien warmth-tolerant forest plantations of red oak ( Quercus rubra), common beech ( Fagus sylvatica) and European larch ( Larix decidua). We compared the changes in foliar litterfall mass and biochemical composition after five months of cold period. The mean mass of fresh foliar litterfall collected in late autumn was 30% higher in red oak compared to the larch and beech plantations. After the cold period, the reduction of foliar litterfall mass did not exceed 10% in any of the studied plantations. The fresh foliar litterfall of red oak was the richest in cellular fibre and easily decomposable glucose and nutrients such as P and Mg, larch was distinguished by the highest lignin, N, K and Ca concentrations, while beech fresh foliar litterfall was the poorest in the aforementioned nutrients. After the cold period, the changes in the biochemical composition of foliar litterfall revealed different patterns. In the spring, the beech and red oak foliar litterfall was the richest in N, P and Ca, meanwhile the larch foliar litterfall still had the highest concentration of lignin but, in contrast to the autumn, was the poorest in nutrients. After the cold period Lignin: N, C: N and C: P ratios reached critical values indicating that the foliar litterfall of beech and red oak had started to decompose. The highest lignin concentration and the highest and most stable Lignin: N, C: N, C: P and N: P ratios after the cold period indicated that the slowest foliar litterfall decomposition took place in the larch plantation.

  17. Subcellular Nutrient Element Localization and Enrichment in Ecto- and Arbuscular Mycorrhizas of Field-Grown Beech and Ash Trees Indicate Functional Differences

    PubMed Central

    Seven, Jasmin; Polle, Andrea

    2014-01-01

    Mycorrhizas are the chief organ for plant mineral nutrient acquisition. In temperate, mixed forests, ash roots (Fraxinus excelsior) are colonized by arbuscular mycorrhizal fungi (AM) and beech roots (Fagus sylvatica) by ectomycorrhizal fungi (EcM). Knowledge on the functions of different mycorrhizal species that coexist in the same environment is scarce. The concentrations of nutrient elements in plant and fungal cells can inform on nutrient accessibility and interspecific differences of mycorrhizal life forms. Here, we hypothesized that mycorrhizal fungal species exhibit interspecific differences in mineral nutrient concentrations and that the differences correlate with the mineral nutrient concentrations of their associated root cells. Abundant mycorrhizal fungal species of mature beech and ash trees in a long-term undisturbed forest ecosystem were the EcM Lactarius subdulcis, Clavulina cristata and Cenococcum geophilum and the AM Glomus sp. Mineral nutrient subcellular localization and quantities of the mycorrhizas were analysed after non-aqueous sample preparation by electron dispersive X-ray transmission electron microscopy. Cenococcum geophilum contained the highest sulphur, Clavulina cristata the highest calcium levels, and Glomus, in which cations and P were generally high, exhibited the highest potassium levels. Lactarius subdulcis-associated root cells contained the highest phosphorus levels. The root cell concentrations of K, Mg and P were unrelated to those of the associated fungal structures, whereas S and Ca showed significant correlations between fungal and plant concentrations of those elements. Our results support profound interspecific differences for mineral nutrient acquisition among mycorrhizas formed by different fungal taxa. The lack of correlation between some plant and fungal nutrient element concentrations may reflect different retention of mineral nutrients in the fungal part of the symbiosis. High mineral concentrations, especially of

  18. Reconstruction of a beech population bottleneck using archival demographic information and Bayesian analysis of genetic data.

    PubMed

    Lander, Tonya A; Oddou-Muratorio, Sylvie; Prouillet-Leplat, Helene; Klein, Etienne K

    2011-12-01

    Range expansion and contraction has occurred in the history of most species and can seriously impact patterns of genetic diversity. Historical data about range change are rare and generally appropriate for studies at large scales, whereas the individual pollen and seed dispersal events that form the basis of geneflow and colonization generally occur at a local scale. In this study, we investigated range change in Fagus sylvatica on Mont Ventoux, France, using historical data from 1838 to the present and approximate Bayesian computation (ABC) analyses of genetic data. From the historical data, we identified a population minimum in 1845 and located remnant populations at least 200 years old. The ABC analysis selected a demographic scenario with three populations, corresponding to two remnant populations and one area of recent expansion. It also identified expansion from a smaller ancestral population but did not find that this expansion followed a population bottleneck, as suggested by the historical data. Despite a strong support to the selected scenario for our data set, the ABC approach showed a low power to discriminate among scenarios on average and a low ability to accurately estimate effective population sizes and divergence dates, probably due to the temporal scale of the study. This study provides an unusual opportunity to test ABC analysis in a system with a well-documented demographic history and identify discrepancies between the results of historical, classical population genetic and ABC analyses. The results also provide valuable insights into genetic processes at work at a fine spatial and temporal scale in range change and colonization.

  19. MULCHES AND OTHER COVER MATERIALS TO REDUCE WEED GROWTH IN CONTAINER-GROWN NURSERY STOCK.

    PubMed

    Rys, F; Van Wesemael, D; Van Haecke, D; Mechant, E; Gobin, B

    2014-01-01

    Due to the recent EU-wide implementation of Integrated Pest Management (IPM), alternative methods to reduce weed growth in container-grown nursery stock are needed to cut back the use of herbicides. Covering the upper layer of the substrate is known as a potential method to prevent or reduce weed growth in plant containers. As a high variety of mulches and other cover materials are on the market, however, it is no longer clear for growers which cover material is most efficient for use in containers. Therefore, we examined the effect on weed growth of different mulches and other cover materials, including Pinus maritima, P. sylvestris, Bio-Top Basic, Bio-Top Excellent, coco chips fine, hemp fibres, straw pellets, coco disk 180LD and jute disk. Cover materials were applied immediately after repotting of Ligustrum ovalifolium or planting of Fagus sylvatica. At regular times, both weed growth and side effects (e.g., plant growth, water status of the substrate, occurrence of mushrooms, foraging of birds, complete cover of the substrate and fixation) were assessed. All examined mulches or other cover materials were able to reduce weed growth on the containers during the whole growing season. Weed suppression was even better than that of a chemical treated control. Although all materials showed some side effects, the impact on plant growth is most important to the grower and depends not only on material characteristics (e.g., biodegradation, nutrient leaching and N-immobilisation) but also on container size and climatic conditions. In conclusion, mulches and other cover materials can be a valuable tool within IPM to lower herbicide use. To enable a deliberate choice of which cover material is best used in a specific situation more research is needed on lifespan and stability as well as on economic characteristics of the materials.

  20. Response of tree growth and species coexistence to density and species evenness in a young forest plantation with two competing species

    PubMed Central

    Collet, Catherine; Ningre, François; Barbeito, Ignacio; Arnaud, Anthony; Piboule, Alexandre

    2014-01-01

    Background and Aims There is considerable evidence for the presence of positive species diversity–productivity relationships in plant populations, but the population parameters determining the type and strength of the relationship are poorly defined. Relationships between species evenness and tree survival or species coexistence are not well established. The objective of this study was to quantify the joint effects of density and species evenness on tree productivity and species coexistence. Methods A 12-year-old experimental tree plantation mixing two species according to a double gradient of density and species proportion was used. A neighbourhood approach was employed and descriptors of local competition were used to model individual tree growth. Fagus sylvatica and Acer pseudoplatanus were used as model species, as they can be considered as ecologically equivalent in their young stages. Key Results Density and tree size were primary factors determining individual growth and stand productivity. Species identity had a significant, but less pronounced, role. Stand productivity was highest when species evenness was close to 1 and slightly lower in uneven mixtures. The reduction in stand productivity when species evenness decreased was of similar magnitude irrespective of which species became dominant, indicating symmetric effects for the two species. When examining individual tree growth in response to species proportion for each species separately, it was observed for both species that individual trees exhibited greater growth in uneven mixtures in which the other species was more frequent. Conclusions The results suggest that mixtures of these two functionally similar species have the highest production at maximum evenness, indicating a complementary effect between them. The presence of a mixture combines both stabilizing mechanisms (individuals from both species show higher growth when surrounded by individuals from the other species) and equalizing mechanisms

  1. Soil H₂¹⁸O labelling reveals the effect of drought on C¹⁸OO fluxes to the atmosphere.

    PubMed

    Barthel, Matti; Sturm, Patrick; Hammerle, Albin; Buchmann, Nina; Gentsch, Lydia; Siegwolf, Rolf; Knohl, Alexander

    2014-11-01

    Above- and belowground processes in plants are tightly coupled via carbon and water fluxes through the soil-plant-atmosphere system. The oxygen isotopic composition of atmospheric CO₂ and water vapour (H₂Ov) provides a valuable tool for investigating the transport and cycling of carbon and water within this system. However, detailed studies on the coupling between ecosystem components and environmental drivers are sparse. Therefore, we conducted a H2 (18)O-labelling experiment to investigate the effect of drought on the speed of the link between below- and aboveground processes and its subsequent effect on C(18)OO released by leaves and soils. A custom-made chamber system, separating shoot from soil compartments, allowed separate measurements of shoot- and soil-related processes under controlled conditions. Gas exchange of oxygen stable isotopes in CO₂ and H₂Ov served as the main tool of investigation and was monitored in real time on Fagus sylvatica saplings using laser spectroscopy. H₂(18)O-labelling showed that drought caused a slower transport of water molecules from soil to shoot, which was indicated by its direct derivation from independently measured concentrations and (18)O/(16)O ratios of CO₂ and H₂Ov, respectively. Furthermore, drought reduced the (18)O equilibrium between H₂O and CO₂ at the shoot level, resulting in less-enriched C(18)OO fluxes from leaf to atmosphere compared with control plants. Compared with the shoot, (18)O equilibrium was not instantaneous in the soil and no drought effect was apparent.

  2. Estimating forest species abundance through linear unmixing of CHRIS/PROBA imagery

    NASA Astrophysics Data System (ADS)

    Stagakis, Stavros; Vanikiotis, Theofilos; Sykioti, Olga

    2016-09-01

    The advancing technology of hyperspectral remote sensing offers the opportunity of accurate land cover characterization of complex natural environments. In this study, a linear spectral unmixing algorithm that incorporates a novel hierarchical Bayesian approach (BI-ICE) was applied on two spatially and temporally adjacent CHRIS/PROBA images over a forest in North Pindos National Park (Epirus, Greece). The scope is to investigate the potential of this algorithm to discriminate two different forest species (i.e. beech - Fagus sylvatica, pine - Pinus nigra) and produce accurate species-specific abundance maps. The unmixing results were evaluated in uniformly distributed plots across the test site using measured fractions of each species derived by very high resolution aerial orthophotos. Landsat-8 images were also used to produce a conventional discrete-type classification map of the test site. This map was used to define the exact borders of the test site and compare the thematic information of the two mapping approaches (discrete vs abundance mapping). The required ground truth information, regarding training and validation of the applied mapping methodologies, was collected during a field campaign across the study site. Abundance estimates reached very good overall accuracy (R2 = 0.98, RMSE = 0.06). The most significant source of error in our results was due to the shadowing effects that were very intense in some areas of the test site due to the low solar elevation during CHRIS acquisitions. It is also demonstrated that the two mapping approaches are in accordance across pure and dense forest areas, but the conventional classification map fails to describe the natural spatial gradients of each species and the actual species mixture across the test site. Overall, the BI-ICE algorithm presented increased potential to unmix challenging objects with high spectral similarity, such as different vegetation species, under real and not optimum acquisition conditions. Its

  3. Impact of Leaf Traits on Temporal Dynamics of Transpired Oxygen Isotope Signatures and Its Impact on Atmospheric Vapor

    PubMed Central

    Dubbert, Maren; Kübert, Angelika; Werner, Christiane

    2017-01-01

    Oxygen isotope signatures of transpiration (δE) are powerful tracers of water movement from plant to global scale. However, a mechanistic understanding of how leaf morphological/physiological traits effect δE is missing. A laser spectrometer was coupled to a leaf-level gas-exchange system to measure fluxes and isotopic signatures of plant transpiration under controlled conditions in seven distinct species (Fagus sylvatica, Pinus sylvestris, Acacia longifolia, Quercus suber, Coffea arabica, Plantago lanceolata, Oxalis triangularis). We analyzed the role of stomatal conductance (gs) and leaf water content (W) on the temporal dynamics of δE following changes in relative humidity (rH). Changes in rH were applied from 60 to 30% and from 30 to 60%, which is probably more than covering the maximum step changes occurring under natural conditions. Further, the impact of gs and W on isotopic non-steady state isofluxes was analyzed. Following changes in rH, temporal development of δE was well described by a one-pool modeling approach for most species. Isofluxes of δE were dominantly driven by stomatal control on E, particularly for the initial period of 30 min following a step change. Hence, the deviation of isofluxes from isotopic steady state can be large, even though plants transpire near to isotopic steady state. Notably, not only transpiration rate and stomatal conductance, but also the leaf traits stomatal density (as a measure of gmax) and leaf water content are significantly related to the time constant (τ) and non-steady-state isofluxes. This might provide an easy-to-access means of a priori assumptions for the impact of isotopic non-steady-state transpiration in various ecosystems. We discuss the implications of our results from leaf to ecosystem scale. PMID:28149303

  4. Overexpression of a Protein Phosphatase 2C from Beech Seeds in Arabidopsis Shows Phenotypes Related to Abscisic Acid Responses and Gibberellin Biosynthesis1

    PubMed Central

    Reyes, David; Rodríguez, Dolores; González-García, Mary Paz; Lorenzo, Oscar; Nicolás, Gregorio; García-Martínez, José Luis; Nicolás, Carlos

    2006-01-01

    A functional abscisic acid (ABA)-induced protein phosphatase type 2C (PP2C) was previously isolated from beech (Fagus sylvatica) seeds (FsPP2C2). Because transgenic work is not possible in beech, in this study we overexpressed this gene in Arabidopsis (Arabidopsis thaliana) to provide genetic evidence on FsPP2C2 function in seed dormancy and other plant responses. In contrast with other PP2Cs described so far, constitutive expression of FsPP2C2 in Arabidopsis, under the cauliflower mosaic virus 35S promoter, produced enhanced sensitivity to ABA and abiotic stress in seeds and vegetative tissues, dwarf phenotype, and delayed flowering, and all these effects were reversed by gibberellic acid application. The levels of active gibberellins (GAs) were reduced in 35S:FsPP2C2 plants, although transcript levels of AtGA20ox1 and AtGA3ox1 increased, probably as a result of negative feedback regulation, whereas the expression of GASA1 was induced by GAs. Additionally, FsPP2C2-overexpressing plants showed a strong induction of the Responsive to ABA 18 (RAB18) gene. Interestingly, FsPP2C2 contains two nuclear targeting sequences, and transient expression assays revealed that ABA directed this protein to the nucleus. Whereas other plant PP2Cs have been shown to act as negative regulators, our results support the hypothesis that FsPP2C2 is a positive regulator of ABA. Moreover, our results indicate the existence of potential cross-talk between ABA signaling and GA biosynthesis. PMID:16815952

  5. Vertical canopy gradient in photosynthesis and monoterpenoid emissions: An insight into the chemistry and physiology behind

    NASA Astrophysics Data System (ADS)

    Šimpraga, M.; Verbeeck, H.; Bloemen, J.; Vanhaecke, L.; Demarcke, M.; Joó, E.; Pokorska, O.; Amelynck, C.; Schoon, N.; Dewulf, J.; Van Langenhove, H.; Heinesch, B.; Aubinet, M.; Steppe, K.

    2013-12-01

    It is well known that vertical canopy gradients and varying sky conditions influence photosynthesis (Pn), specific leaf area (SLA), leaf thickness (LT) and leaf pigments (lutein, â-carotene and chlorophyll). In contrast, little is known about these effects on monoterpenoid (MT) emissions. Our study examines simultaneously measured Pn, MT emissions and the MT/Pn ratio along the canopy of an adult European beech tree (Fagus sylvatica L.) in natural forest conditions. Dynamic branch enclosure systems were used at four heights in the canopy (7, 14, 21 and 25 m) in order to establish relationships and better understand the interaction between Pn and MT emissions under both sunny and cloudy sky conditions. Clear differences in Pn, MT emissions and the MT/Pn ratio were detected within the canopy. The highest Pn rates were observed in the sun leaves at 25 m due to the higher intercepted light levels, whereas MT emissions (and the MT/Pn ratio) were unexpectedly highest in the semi-shaded leaves at 21 m. The higher Pn rates and, apparently contradictory, lower MT emissions in the sun leaves may be explained by the hypothesis of Owen and Peñuelas (2005), stating synthesis of more photo-protective carotenoids may decrease the emissions of volatile isoprenoids (including MTs) because they both share the same biochemical precursors. In addition, leaf traits like SLA, LT and leaf pigments clearly differed with height in the canopy, suggesting that the leaf's physiological status cannot be neglected in future research on biogenic volatile organic compounds (BVOCs) when aiming at developing new and/or improved emission algorithms.

  6. Forest Water Stress Modelling: Comparison With Long-term Micrometeorological Observations

    NASA Astrophysics Data System (ADS)

    Rivalland, V.; Calvet, J.-C.; Brunet, Y.; Granier, A.; Guehl, J.-M.; Picon-Cochard, C.

    The effect of drought on the parameters of a model of plant stomatal conductance is investigated in the case of woody plants, based on a large number of published leaf-level data. Thirty two experimental data sets are analysed in order to under- stand the inter-specific variations of the conductance and photosynthesis parameters in unstressed conditions. Four data sets of the same study include a soil drying cy- cle under present and doubled atmospheric CO2 concentration (350 and 700 ppm, respectively) for two tree species displaying markedly different responses to soil wa- ter stress. The behaviour of two model's parameters is explored in both unstressed and stressed conditions: the mesophyll conductance and the maximum ratio between the intercellular and the atmospheric CO2 concentration (gm and fo, respectively, in stressed conditions, and gm* and fo* in unstressed conditions). An interspecific lin- ear relationship between ln(gm*) and fo* is found. A simple parameterisation of the evolution of ln(gm) and fo caused by drought is proposed for two distinct strategies, defensive and offensive. This woody stress parameterisation was implemented into the interaction between soil, vegetation and atmosphere, interactive vegetation model ISBA-A-gs and then tested on two forest canopies for which long-term micrometeo- rological measurements where available. The two forest consist of Pinus pinaster and Fagus sylvatica species, respectively, and are both sites of the European network Eu- roflux. Moreover, on the Pinus pinaster site, we tested a methodology to identify the understorey (Molinia coerulea) response to stress based on micrometeorological and physiological measurements.

  7. Characterising invasive non-native Rhododendron ponticum spectra signatures with spectroradiometry in the laboratory and field: Potential for remote mapping

    NASA Astrophysics Data System (ADS)

    Taylor, Sarah L.; Hill, Ross A.; Edwards, Colin

    2013-07-01

    Compared with traditional ground surveys, remote sensing has the potential to map the spatial extent of non-native invasive species rapidly and reliably. This paper assesses the potential of spectroradiometry to distinguish and characterise the status of invasive non-native rhododendron (Rhododendron ponticum). Absolute reflectance of target plant material was measured with an ASD Fieldspec Pro System under standardised laboratory conditions and in the field to characterise spectral signatures in the winter, during leaf-off conditions for woodland overstory, and in the summer when mature rhododendrons are flowering. A logistic regression model of absolute reflectance at key wavelengths (490, 550, 610, 1040 and 1490 nm) was used to determine the success of discriminating rhododendron from three other shrubby species likely to be encountered in woodlands during the winter. The logistic regression model was highly significant (p < 0.001), with 93.5% of 246 leaf sets correctly identified as rhododendron or non-rhododendron (i.e. cherry laurel (Prunus laurocerasus), holly (Ilex aquifolium), and beech (Fagus sylvatica)). Rescaling the data to emulate the spectral resolution of airborne and satellite acquired data decreased the total success rate of correctly identifying rhododendron by only 0.4%; although this error rate will likely increase for airborne or satellite data as a result of atmospheric attenuation and reduced spatial resolution. This demonstrates the potential to map bush presence using hyperspectral data and indicates the optimum spectral wavelengths required. Such information is critical to the development of successful strategic management plans to eradicate rhododendron (and the associated Phytophthora ramorum pathogen) effectively from a site.

  8. Transpiration of urban trees and its cooling effect in a high latitude city.

    PubMed

    Konarska, Janina; Uddling, Johan; Holmer, Björn; Lutz, Martina; Lindberg, Fredrik; Pleijel, Håkan; Thorsson, Sofia

    2016-01-01

    An important ecosystem service provided by urban trees is the cooling effect caused by their transpiration. The aim of this study was to quantify the magnitude of daytime and night-time transpiration of common urban tree species in a high latitude city (Gothenburg, Sweden), to analyse the influence of weather conditions and surface permeability on the tree transpiration, and to find out whether tree transpiration contributed to daytime or nocturnal cooling. Stomatal conductance and leaf transpiration at day and night were measured on mature street and park trees of seven common tree species in Gothenburg: Tilia europaea, Quercus robur, Betula pendula, Acer platanoides, Aesculus hippocastanum, Fagus sylvatica and Prunus serrulata. Transpiration increased with vapour pressure deficit and photosynthetically active radiation. Midday rates of sunlit leaves ranged from less than 1 mmol m(-2) s(-1) (B. pendula) to over 3 mmol m(-2) s(-1) (Q. robur). Daytime stomatal conductance was positively related to the fraction of permeable surfaces within the vertically projected crown area. A simple estimate of available rainwater, comprising of precipitation sum and fractional surface permeability within the crown area, was found to explain 68% of variation in midday stomatal conductance. Night-time transpiration was observed in all studied species and amounted to 7 and 20% of midday transpiration of sunlit and shaded leaves, respectively. With an estimated night-time latent heat flux of 24 W m(-2), tree transpiration significantly increased the cooling rate around and shortly after sunset, but not later in the night. Despite a strong midday latent heat flux of 206 W m(-2), a cooling effect of tree transpiration was not observed during the day.

  9. The dynamic of annual carbon allocation to wood in European forests is consistent with a combined source-sink limitation of growth: implications for modelling

    NASA Astrophysics Data System (ADS)

    Guillemot, J.; Martin-StPaul, N. K.; Dufrêne, E.; François, C.; Soudani, K.; Ourcival, J. M.; Delpierre, N.

    2015-02-01

    The extent to which forest growth is limited by carbon (C) supply (source control) or by cambial activity (sink control) will condition the response of trees to global changes. However, the physiological processes responsible for the limitation of forest growth are still under debate. The aim of this study is to evaluate the key drivers of the annual carbon allocation to wood along large soil and climate regional gradients in five tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex, Quercus robur and Picea abies). Combining field measurements and process-based simulations at 49 sites (931 site-years), we assessed the stand biomass growth dependences at both inter-site and inter-annual scales. Specifically, the relative influence of forest C balance (source control), direct environmental control (water and temperature controls of sink activity) and allocation adjustments related to age, past climate conditions, competition intensity and soil nutrient availability on growth were quantified. The inter-site variability in stand C allocation to wood was predominantly driven by an age-related decline. The direct control of temperature or water stress on sink activity (i.e. independently from their effects on C supply) exerted a strong influence on the annual stand woody growth in all the species considered, including deciduous temperate species. The lagged effect of the past environment conditions was a significant driver of the annual C allocation to wood. Carbon supply appeared to strongly limit growth only in deciduous temperate species. We provide an evaluation of the spatio-temporal dynamics of annual carbon allocation to wood in European forests. Our study supports the premise that European forest growth is under a complex control including both source and sink limitations. The relative influences of the different growth drivers strongly vary across years and spatial ecological gradients. We suggest a

  10. The shifting phenological landscape: Within- and between-species variation in leaf emergence in a mixed-deciduous woodland.

    PubMed

    Cole, Ella F; Sheldon, Ben C

    2017-02-01

    Many organisms rely on synchronizing the timing of their life-history events with those of other trophic levels-known as phenological matching-for survival or successful reproduction. In temperate deciduous forests, the extent of matching with the budburst date of key tree species is of particular relevance for many herbivorous insects and, in turn, insectivorous birds. In order to understand the ecological and evolutionary forces operating in these systems, we require knowledge of the factors influencing leaf emergence of tree communities. However, little is known about how phenology at the level of individual trees varies across landscapes, or how consistent this spatial variation is between different tree species. Here, we use field observations, collected over 2 years, to characterize within- and between-species differences in spring phenology for 825 trees of six species (Quercus robur, Fraxinus excelsior, Fagus sylvatica, Betula pendula, Corylus avellana, and Acer pseudoplatanus) in a 385-ha woodland. We explore environmental predictors of individual variation in budburst date and bud development rate and establish how these phenological traits vary over space. Trees of all species showed markedly consistent individual differences in their budburst timing. Bud development rate also varied considerably between individuals and was repeatable in oak, beech, and sycamore. We identified multiple predictors of budburst date including altitude, local temperature, and soil type, but none were universal across species. Furthermore, we found no evidence for interspecific covariance of phenology over space within the woodland. These analyses suggest that phenological landscapes are highly complex, varying over small spatial scales both within and between species. Such spatial variation in vegetation phenology is likely to influence patterns of selection on phenology within populations of consumers. Knowledge of the factors shaping the phenological environments

  11. Observations of the uptake of carbonyl sulfide (COS) by trees under elevated atmospheric carbon dioxide concentrations

    NASA Astrophysics Data System (ADS)

    Sandoval-Soto, L.; Kesselmeier, M.; Schmitt, V.; Wild, A.; Kesselmeier, J.

    2012-08-01

    Global change forces ecosystems to adapt to elevated atmospheric concentrations of carbon dioxide (CO2). We understand that carbonyl sulfide (COS), a trace gas which is involved in building up the stratospheric sulfate aerosol layer, is taken up by vegetation with the same triad of the enzymes which are metabolizing CO2, i.e. ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), phosphoenolpyruvate carboxylase (PEP-Co) and carbonic anhydrase (CA). Therefore, we discuss a physiological/biochemical acclimation of these enzymes affecting the sink strength of vegetation for COS. We investigated the acclimation of two European tree species, Fagus sylvatica and Quercus ilex, grown inside chambers under elevated CO2, and determined the exchange characteristics and the content of CA after a 1-2 yr period of acclimation from 350 ppm to 800 ppm CO2. We demonstrate that a compensation point, by definition, does not exist. Instead, we propose to discuss a point of uptake affinity (PUA). The results indicate that such a PUA, the CA activity and the deposition velocities may change and may cause a decrease of the COS uptake by plant ecosystems, at least as long as the enzyme acclimation to CO2 is not surpassed by an increase of atmospheric COS. As a consequence, the atmospheric COS level may rise causing an increase of the radiative forcing in the troposphere. However, this increase is counterbalanced by the stronger input of this trace gas into the stratosphere causing a stronger energy reflection by the stratospheric sulfur aerosol into space (Brühl et al., 2012). These data are very preliminary but may trigger a discussion on COS uptake acclimation to foster measurements with modern analytical instruments.

  12. Disparity in elevational shifts of European trees in response to recent climate warming.

    PubMed

    Rabasa, Sonia G; Granda, Elena; Benavides, Raquel; Kunstler, Georges; Espelta, Josep M; Ogaya, Romá; Peñuelas, Josep; Scherer-Lorenzen, Michael; Gil, Wojciech; Grodzki, Wojciech; Ambrozy, Slawomir; Bergh, Johan; Hódar, José A; Zamora, Regino; Valladares, Fernando

    2013-08-01

    Predicting climate-driven changes in plant distribution is crucial for biodiversity conservation and management under recent climate change. Climate warming is expected to induce movement of species upslope and towards higher latitudes. However, the mechanisms and physiological processes behind the altitudinal and latitudinal distribution range of a tree species are complex and depend on each tree species features and vary over ontogenetic stages. We investigated the altitudinal distribution differences between juvenile and adult individuals of seven major European tree species along elevational transects covering a wide latitudinal range from southern Spain (37°N) to northern Sweden (67°N). By comparing juvenile and adult distributions (shifts on the optimum position and the range limits) we assessed the response of species to present climate conditions in relation to previous conditions that prevailed when adults were established. Mean temperature increased by 0.86 °C on average at our sites during the last decade compared with previous 30-year period. Only one of the species studied, Abies alba, matched the expected predictions under the observed warming, with a maximum abundance of juveniles at higher altitudes than adults. Three species, Fagus sylvatica, Picea abies and Pinus sylvestris, showed an opposite pattern while for other three species, such as Quercus ilex, Acer pseudoplatanus and Q. petraea, we were no able to detect changes in distribution. These findings are in contrast with theoretical predictions and show that tree responses to climate change are complex and are obscured not only by other environmental factors but also by internal processes related to ontogeny and demography.

  13. Changes in thermal infrared spectra of plants caused by temperature and water stress

    NASA Astrophysics Data System (ADS)

    Buitrago, Maria F.; Groen, Thomas A.; Hecker, Christoph A.; Skidmore, Andrew K.

    2016-01-01

    Environmental stress causes changes in leaves and the structure of plants. Although physiological adaptations to stress by plants have been explored, the effect of stress on the spectral properties in the thermal part of the electromagnetic spectrum (3-16 μm) has not yet been investigated. In this research two plant species (European beech, Fagus sylvatica and rhododendron, Rhododendron cf. catawbiense) that both grow naturally under temperature limited conditions were selected, representing deciduous and evergreen plants respectively. Besides TIR spectra, Leaf Water Content (LWC) and cuticle thickness were measured as possible variables that can explain the changes in TIR spectra. The results demonstrated that both species, when exposed to either water or temperature stress, showed significant changes in their TIR spectra. The changes in TIR in response to stress were similar within a species, regardless of the stress imposed on them. However, changes in TIR spectra differed between species. For rhododendron emissivity in TIR increased under stress while for beech it decreased. Both species showed depletion of Leaf Water Content (LWC) under stress, ruling LWC out as a main cause for the change in the TIR spectra. Cuticle thickness remained constant for beech, but increased for rhododendron. This suggests that changes in emissivity may be linked to changes in the cuticle thickness and possibly the structure of cuticle. It is known that spectral changes in this region have a close connection with microstructure and biochemistry of leaves. We propose detailed measurements of these changes in the cuticle to analyze the effect of microstructure on TIR spectra.

  14. Development and verification of a water and sugar transport model using measured stem diameter variations.

    PubMed

    De Schepper, Veerle; Steppe, Kathy

    2010-05-01

    In trees, water and sugars are transported by xylem and phloem conduits which are hydraulically linked. A simultaneous study of both flows is interesting, since they concurrently influence important processes such as stomatal regulation and growth. A few mathematical models have already been developed to investigate the influence of both hydraulically coupled flows. However, none of these models has so far been tested using real measured field data. In the present study, a comprehensive whole-tree model is developed that enables simulation of the stem diameter variations driven by both the water and sugar transport. Stem diameter variations are calculated as volume changes of both the xylem and the phloem tissue. These volume changes are dependent on: (i) water transport according to the cohesion-tension theory; (ii) sugar transport according to the Münch hypothesis; (iii) loading and unloading of sugars; and (iv) irreversible turgor-driven growth. The model considers three main compartments (crown, stem, and roots) and is verified by comparison with actual measured stem diameter variations and xylem sap flow rates. These measurements were performed on a young oak (Quercus robur L.) tree in controlled conditions and on an adult beech (Fagus sylvatica L.) tree in a natural forest. A good agreement was found between simulated and measured data. Hence, the model seemed to be a realistic representation of the processes observed in reality. Furthermore, the model is able to simulate several physiological variables which are relatively difficult to measure: phloem turgor, phloem osmotic pressure, and Münch's counterflow. Simulation of these variables revealed daily dynamics in their behaviour which were mainly induced by transpiration. Some of these dynamics are experimentally confirmed in the literature, while others are not.

  15. Fine root decomposition rates do not mirror those of leaf litter among temperate tree species.

    PubMed

    Hobbie, Sarah E; Oleksyn, Jacek; Eissenstat, David M; Reich, Peter B

    2010-02-01

    Elucidating the function of and patterns among plant traits above ground has been a major research focus, while the patterns and functioning of belowground traits remain less well understood. Even less well known is whether species differences in leaf traits and their associated biogeochemical effects are mirrored by differences in root traits and their effects. We studied fine root decomposition and N dynamics in a common garden study of 11 temperate European and North American tree species (Abies alba, Acer platanoides, Acer pseudoplatanus, Carpinus betulus, Fagus sylvatica, Larix decidua, Picea abies, Pseudotsuga menziesii, Quercus robur, Quercus rubra and Tilia cordata) to determine whether leaf litter and fine root decomposition rates are correlated across species as well as which species traits influence microbial decomposition above versus below ground. Decomposition and N immobilization rates of fine roots were unrelated to those of leaf litter across species. The lack of correspondence of above- and belowground processes arose partly because the tissue traits that influenced decomposition and detritus N dynamics different for roots versus leaves, and partly because influential traits were unrelated between roots and leaves across species. For example, while high hemicellulose concentrations and thinner roots were associated with more rapid decomposition below ground, low lignin and high Ca concentrations were associated with rapid aboveground leaf decomposition. Our study suggests that among these temperate trees, species effects on C and N dynamics in decomposing fine roots and leaf litter may not reinforce each other. Thus, species differences in rates of microbially mediated decomposition may not be as large as they would be if above- and belowground processes were working in similar directions (i.e., if faster decomposition above ground corresponded to faster decomposition below ground). Our results imply that studies that focus solely on aboveground

  16. Planting sentinel European trees in eastern Asia as a novel method to identify potential insect pest invaders.

    PubMed

    Roques, Alain; Fan, Jian-Ting; Courtial, Béatrice; Zhang, Yan-Zhuo; Yart, Annie; Auger-Rozenberg, Marie-Anne; Denux, Olivier; Kenis, Marc; Baker, Richard; Sun, Jiang-Hua

    2015-01-01

    Quarantine measures to prevent insect invasions tend to focus on well-known pests but a large proportion of the recent invaders were not known to cause significant damage in their native range, or were not even known to science before their introduction. A novel method is proposed to detect new potential pests of woody plants in their region of origin before they are introduced to a new continent. Since Asia is currently considered to be the main supplier of insect invaders to Europe, sentinel trees were planted in China during 2007-2011 as an early warning tool to identify the potential for additional Asian insect species to colonize European trees. Seedlings (1-1.5 m tall) of five broadleaved (Quercus petraea, Q. suber, Q. ilex, Fagus sylvatica, and Carpinus betulus) and two conifer species (Abies alba and Cupressus sempervirens) were planted in blocks of 100 seedlings at two widely separated sites (one in a nursery near Beijing and the other in a forest environment near Fuyang in eastern China), and then regularly surveyed for colonization by insects. A total of 104 insect species, mostly defoliators, were observed on these new hosts, and at least six species were capable of larval development. Although a number of the insects observed were probably incidental feeders, 38 species had more than five colonization events, mostly infesting Q. petraea, and could be considered as being capable of switching to European trees if introduced to Europe. Three years was shown to be an appropriate duration for the experiment, since the rate of colonization then tended to plateau. A majority of the identified species appeared to have switched from agricultural crops and fruit trees rather than from forest trees. Although these results are promising, the method is not appropriate for xylophagous pests and other groups developing on larger trees. Apart from the logistical problems, the identification to species level of the specimens collected was a major difficulty. This

  17. Within-stand variability of leaf phenology in deciduous tree species: characterization and ecological implications

    NASA Astrophysics Data System (ADS)

    Delpierre, N.; Cecchini, S.; Dufrêne, E.; Guillemot, J.; Nicolas, M.

    2014-12-01

    The vast majority of phenological studies address questions relative to the spatial or temporal variability of phenological timings integrated at the forest stand (i.e. tree population) scale. Within a forest stand, the inter-individual variability of phenological timings is expected to affect a range of tree functions among which the access to light, the use of carbon and nitrogen reserves, the absorption of minerals and the sensitivity to pathogens. Hence the individual's phenological traits are likely to be strongly selected, resulting in an adaptation of the population to local conditions, as evidenced by latitudinal and altitudinal clines observed in common garden experiments. Studies dedicated to the within-stand variability of the timing of phenophases have to date been mostly designed for contrasting the behaviours of understory versus overstory species or seedlings compared to their adult conspecifics. The few published papers studying the phenological timings among adult conspecifics revealed unclear patterns. We aimed at clarifying the understanding of the within-stand variability of tree phenology of three of the main European deciduous species (Quercus petraea, Quercus robur and Fagus sylvatica) through the analysis of a unique phenological database collected over 44 (28 Oak sites, 16 Beech stands) forest stands at the tree level for 4 years over France. We show that within a forest stand, individual trees have a distinct "phenological identity" resulting in a year to year conservation of (a) the individuals' spring and autumn phenological rankings and (b) the individuals' critical temperature sums required for budburst and senescence. The individual's spring "phenological identity" affects its functioning and, ultimately, its competitive ability: big trees burst earlier. Acknowledging that Angiosperms show low genetic diversity between populations, we show that the between-site variability of critical temperature sums needed for budburst or senescence

  18. Source and compositional changes of soil organic matter in an acidic forest soil - from top- to subsoil

    NASA Astrophysics Data System (ADS)

    Angst, Gerrit; John, Stephan; Rethemeyer, Janet; Kögel-Knabner, Ingrid; Mueller, Carsten W.

    2014-05-01

    Subsoils can significantly contribute to the terrestrial C pool. While processes of C turnover and storage in topsoils are generally well understood, little is known about subsoils. Our project, embedded within the DFG research group FOR 1806, aims to contribute to the knowledge about subsoil C by differentiating soil organic matter (SOM) in terms of its origin and its composition. In order to obtain a meaningful sample set we studied three soil ditches, 3.15 m in length and 2.15 m in depth, in a podzolic Cambisol under European beech (Fagus sylvatica L.) north of Hannover, Germany. In a to date unique sampling approach we took 64 soil samples in a regular vertical grid in each of the soil profiles, thus identifying possible gradients between top- and subsoil. The samples were subjected to a combined density and particle size fractionation to separate particulate organic matter (POM) from mineral compartments. We especially aimed at obtaining the combined fine silt and clay fraction which is thought to be most important in the long term stabilization of SOM. The chemical composition of the so obtained fractions and the bulk soil was revealed by C, N and 13C CPMAS NMR measurements. The source of OM in the soil was investigated by tracing the biopolymers cutin and suberin across the soil profile. Cutin occurs mainly in the cuticula of leaves while suberin mainly constitutes the endodermal cell walls of plant roots. In soils the two polymers can thus be used as proxies for above and belowground OM input respectively. To release the constituting monomers of the two biopolymers from the soil samples the latter were pretreated with organic solvents to extract free lipids. The soil residues were subsequently subjected to a base hydrolysis and the so obtained extracts were measured with GC/MS. The organic C contents of the bulk soil decrease significantly with depth in all transects from around 15 mg g-1 to 2 mg g-1. This is likely associated with the very high sand and

  19. Clues for regulatory processes in fungal uptake and transfer of minerals to the basidiospore.

    PubMed

    Gramss, Gerhard; Voigt, Klaus-Dieter

    2013-07-01

    Several fungal species are notorious for the preferential acquisition of toxicants such as AsCdHgPbU in their wild-grown basidiomes, but it is not known how, or whether at all, mineral uptake is regulated. In this study, basidiomes of Kuehneromyces mutabilis, Pleurotus ostreatus, and Hypholoma fasciculare were grown on Fagus sylvatica logs embedded in sand, uranium-overburden soil, and garden soil (SIO) at a lab scale to raise the accessible mineral resources 30 to >1,000 times over those available in the timber alone. Non-embedded logs and a field culture established on SIO served as controls. Concentrations of 22 minerals were determined by inductively coupled plasma mass spectrometry from microwave-digested samples of timber, soils, whole and dissected mushrooms, and basidiospores. It was the goal to determine whether mineral uptake rates vary simply with their concentration in the substrate or undergo selections which indicate the ability of metal sensing and optimizing/delimiting the quantity of (essential) elements on their passage from a substrate via basidiome to the basidiospores. It is shown that an underrepresented substrate mineral is up-concentrated to a more or less regulated and physiologically compatible mean, whereas a rising external mineral supply leads to uptake blockage by downregulation of the bioconcentration rate in the vicinity of an apparent mycelial saturation point. The resulting concentrations in whole K. mutabilis basidiomes of the essential metals, CaCoCuFeMgMn(Sr)Zn corresponded surprisingly with those in wheat grains which share the main metabolic pathways with fungi and whose metallome is believed to be out-regulated for an optimum and stress-free development. Concentrations of nonessential metals, too, fitted the range of those common crops, whereas KP reached the higher typical level of fungi. Minerals entering the lower stipe of the K. mutabilis basidiome were specifically enriched/diluted on a passage to the gills and once more

  20. Soil matrix tracer contamination and canopy recycling did not impair ¹³CO₂ plant-soil pulse labelling experiments.

    PubMed

    Barthel, Matthias; Sturm, Patrick; Knohl, Alexander

    2011-09-01

    When conducting (13)CO(2) plant-soil pulse labelling experiments, tracer material might cause unwanted side effects which potentially affect δ(13)C measurements of soil respiration (δ(13)C(SR)) and the subsequent data interpretation. First, when the soil matrix is not isolated from the atmosphere, contamination of the soil matrix with tracer material occurs leading to a physical back-diffusion from soil pores. Second, when using canopy chambers continuously, (13)CO(2) is permanently re-introduced into the atmosphere due to leaf respiration which then aids re-assimilation of tracer material by the canopy. Accordingly, two climate chamber experiments on European beech saplings (Fagus sylvatica L.) were conducted to evaluate the influence of soil matrix (13)CO(2) contamination and canopy recycling on soil (13)CO(2) efflux during (13)CO(2) plant-soil pulse labelling experiments. For this purpose, a combined soil/canopy chamber system was developed which separates soil and canopy compartments in order to (a) prevent diffusion of (13)C tracer into the soil chamber during a (13)CO(2) canopy pulse labelling and (b) study stable isotope processes in soil and canopy individually and independently. In combination with laser spectrometry measuring CO(2) isotopologue mixing ratios at a rate of 1 Hz, we were able to measure δ(13)C in canopy and soil at very high temporal resolution. For the soil matrix contamination experiment, (13)CO(2) was applied to bare soil, canopy only or, simultaneously, to soil and canopy of the beech trees. The obtained δ(13)C(SR) fluxes from the different treatments were then compared with respect to label re-appearance, first peak time and magnitude. By determining the δ(13)C(SR) decay of physical (13)CO(2) back-diffusion from bare soils (contamination), it was possible to separate biological and physical components in δ(13)C(SR) of a combined flux of both. A second pulse labelling experiment, with chambers permanently enclosing the canopy

  1. A discrete element modelling approach for block impacts on trees

    NASA Astrophysics Data System (ADS)

    Toe, David; Bourrier, Franck; Olmedo, Ignatio; Berger, Frederic

    2015-04-01

    These past few year rockfall models explicitly accounting for block shape, especially those using the Discrete Element Method (DEM), have shown a good ability to predict rockfall trajectories. Integrating forest effects into those models still remain challenging. This study aims at using a DEM approach to model impacts of blocks on trees and identify the key parameters controlling the block kinematics after the impact on a tree. A DEM impact model of a block on a tree was developed and validated using laboratory experiments. Then, key parameters were assessed using a global sensitivity analyse. Modelling the impact of a block on a tree using DEM allows taking into account large displacements, material non-linearities and contacts between the block and the tree. Tree stems are represented by flexible cylinders model as plastic beams sustaining normal, shearing, bending, and twisting loading. Root soil interactions are modelled using a rotation stiffness acting on the bending moment at the bottom of the tree and a limit bending moment to account for tree overturning. The crown is taken into account using an additional mass distribute uniformly on the upper part of the tree. The block is represented by a sphere. The contact model between the block and the stem consists of an elastic frictional model. The DEM model was validated using laboratory impact tests carried out on 41 fresh beech (Fagus Sylvatica) stems. Each stem was 1,3 m long with a diameter between 3 to 7 cm. Wood stems were clamped on a rigid structure and impacted by a 149 kg charpy pendulum. Finally an intensive simulation campaign of blocks impacting trees was done to identify the input parameters controlling the block kinematics after the impact on a tree. 20 input parameters were considered in the DEM simulation model : 12 parameters were related to the tree and 8 parameters to the block. The results highlight that the impact velocity, the stem diameter, and the block volume are the three input

  2. Assessing the effect of spatial resolution of regional climate downscaling on the productivity and distribution of three widespread tree species over France

    NASA Astrophysics Data System (ADS)

    Martin-StPaul, Nicolas K.; Stephanon, Marc; Francois, Christophe; Soudani, Kamel; Dufrêne, Eric; Drobinski, Phillipe; Cheaib, Alissar; Ruffault, Julien; Rambal, Serge; Mouillot, Florent; Leadley, Paul

    2013-04-01

    The recent increases in temperature and water deficit as a result of climate changes have already impaired forest functioning and might trigger tree dieback worldwide in the near future. The assessment of future forest conditions relies on mechanistic models that predict changes in trees and forest functioning as a function of meteorological drivers. Currently, global and regional models (GCM and RCM) are the main providers of climate forcing in impact studies. One large uncertainty when forecasting the forest functioning is associated with the coarse spatial resolution of climate scenarii. In this study we assessed how the spatial resolution in climate forcing provided by the RCM WRF impacted the simulated productivity and distribution of three species (Fagus sylvatica, Quercus ilex) over France. We ran the forest model CASTANEA over France (that simulates fluxes of carbon and water and forest growth) using the output of WRF at different spatial scales (50 km, 20km, 8km and 1km) as forcing climate entries. The productivity simulated by CASTANEA was used as a surrogate of beech persistence for the reference period of WRF (1988-2008). Because climate variables simulated by WRF exhibited large bias compared to surface observations, WRF was first corrected using a reference dataset (SAFRAN database) upscaled at the WRF resolution (50km and 20 km). Additionally, on 2 specific limited areas (the Languedoc Roussillon and the Bourgogne region) we used a statistical downscaling of the WRF forcing entries in order to increase the spatial resolution up to 1km. Our results showed that simulations at finer resolution had relatively little impact on the mean and variance of beech productivity over France compared to coarser resolutions. However, at the finest resolutions, we observed strong local gradients with important variations in the mean and the variance of forest productivity (up to 60%). These results are particularly noticeable in regions characterized by complex

  3. Effects of stoichiometry and temperature perturbations on beech leaf litter decomposition, enzyme activities and protein expression

    NASA Astrophysics Data System (ADS)

    Keiblinger, K. M.; Schneider, T.; Roschitzki, B.; Schmid, E.; Eberl, L.; Hämmerle, I.; Leitner, S.; Richter, A.; Wanek, W.; Riedel, K.; Zechmeister-Boltenstern, S.

    2012-11-01

    Microbes are major players in leaf litter decomposition and therefore advances in the understanding of their control on element cycling are of paramount importance. Our aim was to investigate the influence of leaf litter stoichiometry in terms of carbon (C) : nitrogen (N) : phosphorus (P) ratios on the decomposition processes and to track changes in microbial community structures and functions in response to temperature stress treatments. To elucidate how the stoichiometry of beech leaf litter (Fagus sylvatica L.) and stress treatments interactively affect the microbial decomposition processes, a terrestrial microcosm experiment was conducted. Beech litter from different Austrian sites covering C:N ratios from 39 to 61 and C:P ratios from 666 to 1729 were incubated at 15 °C and 60% moisture for six months. Part of the microcosms were then subjected to severe changes in temperature (+30 °C and -15 °C) to monitor the influence of temperature stress. Extracellular enzyme activities were assayed and respiratory activities measured. A semi-quantitative metaproteomics approach (1D-SDS PAGE combined with liquid chromatography and tandem mass spectrometry; unique spectral counting) was employed to investigate the impact of the applied stress treatments in dependency of litter stoichiometry on structure and function of the decomposing community. In litter with narrow C:nutrient (C:N, C:P) ratios, microbial decomposers were most abundant. Cellulase, chitinase, phosphatase and protease activity decreased after heat and freezing treatments. Decomposer communities and specific functions varied with site, i.e. stoichiometry. The applied stress combined with the respective time of sampling evoked changes of enzyme activities and litter pH. Freezing treatments resulted in a decline in residual plant litter material and increased fungal abundance, indicating slightly accelerated decomposition. Overall, a strong effect of litter stoichiometry on microbial community structures and

  4. Short-term natural δ13C and δ18O variations in pools and fluxes in a beech forest: the transfer of isotopic signal from recent photosynthates to soil respired CO2

    NASA Astrophysics Data System (ADS)

    Gavrichkova, O.; Proietti, S.; Moscatello, S.; Portarena, S.; Battistelli, A.; Matteucci, G.; Brugnoli, E.

    2011-10-01

    The fate of photosynthetic products within the plant-soil continuum determines how long the reduced carbon resides within the ecosystem and when it returns back to the atmosphere in the form of respiratory CO2. We have tested the possibility of measuring natural variation in δ13C and δ18O to disentangle the potential times needed to transfer carbohydrates produced by photosynthesis down to trunk, roots and, in general, to belowground up to its further release in the form of soil respiration into the atmosphere in a beech (Fagus sylvatica) forest. We have measured the variation in stable carbon and oxygen isotope compositions in plant material and in soil respired CO2 every three hours for three consecutive days. Possible steps and different signs of post-photosynthetic fractionation during carbon translocation were also identified. A 12 h-periodicity was observed for variation in δ13C in soluble sugars in the top crown leaves and it can be explained by starch day/night dynamics in synthesis and breakdown and by stomatal limitations under elevated vapour pressure deficits. Photosynthetic products were transported down the trunk and mixed with older carbon pools, therefore causing the dampening of the δ13C signal variation. The strongest periodicity of 24 h was found in δ13C in soil respiration indicating changes in root contribution to the total CO2 efflux. Other non-biological causes like diffusion fractionation and advection induced by gas withdrawn from the measurement chamber complicate data interpretation on this step of C transfer path. Nevertheless, it was possible to identify the speed of carbohydrates' translocation from the point of assimilation to the trunk breast height because leaf-imprinted enrichment of δ18O in soluble sugars was less modified along the downward transport and was well related to environmental parameters potentially linked to stomatal conductance. The speed of carbohydrates translocation from the site of assimilation to the trunk

  5. Planting Sentinel European Trees in Eastern Asia as a Novel Method to Identify Potential Insect Pest Invaders

    PubMed Central

    Roques, Alain; Fan, Jian-ting; Courtial, Béatrice; Zhang, Yan-zhuo; Yart, Annie; Auger-Rozenberg, Marie-Anne; Denux, Olivier; Kenis, Marc; Baker, Richard; Sun, Jiang-hua

    2015-01-01

    Quarantine measures to prevent insect invasions tend to focus on well-known pests but a large proportion of the recent invaders were not known to cause significant damage in their native range, or were not even known to science before their introduction. A novel method is proposed to detect new potential pests of woody plants in their region of origin before they are introduced to a new continent. Since Asia is currently considered to be the main supplier of insect invaders to Europe, sentinel trees were planted in China during 2007-2011 as an early warning tool to identify the potential for additional Asian insect species to colonize European trees. Seedlings (1-1.5 m tall) of five broadleaved (Quercus petraea, Q. suber, Q. ilex, Fagus sylvatica, and Carpinus betulus) and two conifer species (Abies alba and Cupressus sempervirens) were planted in blocks of 100 seedlings at two widely separated sites (one in a nursery near Beijing and the other in a forest environment near Fuyang in eastern China), and then regularly surveyed for colonization by insects. A total of 104 insect species, mostly defoliators, were observed on these new hosts, and at least six species were capable of larval development. Although a number of the insects observed were probably incidental feeders, 38 species had more than five colonization events, mostly infesting Q. petraea, and could be considered as being capable of switching to European trees if introduced to Europe. Three years was shown to be an appropriate duration for the experiment, since the rate of colonization then tended to plateau. A majority of the identified species appeared to have switched from agricultural crops and fruit trees rather than from forest trees. Although these results are promising, the method is not appropriate for xylophagous pests and other groups developing on larger trees. Apart from the logistical problems, the identification to species level of the specimens collected was a major difficulty. This

  6. Nurse plants, tree saplings and grazing pressure: changes in facilitation along a biotic environmental gradient.

    PubMed

    Smit, Christian; Vandenberghe, Charlotte; den Ouden, Jan; Müller-Schärer, Heinz

    2007-05-01

    Current conceptual models predict that an increase in stress shifts interactions between plants from competitive to facilitative; hence, facilitation is expected to gain in ecological importance with increasing stress. Little is known about how facilitative interactions between plants change with increasing biotic stress, such as that incurred by consumer pressure or herbivory (i.e. disturbance sensu Grime). In grazed ecosystems, the presence of unpalatable plants is reported to protect tree saplings against cattle grazing and enhance tree establishment. In accordance with current conceptual facilitation-stress models, we hypothesised a positive relationship between facilitation and grazing pressure. We tested this hypothesis in a field experiment in which tree saplings of four different species (deciduous Fagus sylvatica, Acer pseudoplatanus and coniferous Abies alba, Picea abies) were planted either inside or outside of the canopy of the spiny nurse shrub Rosa rubiginosa in enclosures differing in grazing pressure (low and high) and in exclosures. During one grazing season we followed the survival of the different tree saplings and the level of browsing on these; we also estimated browsing damage to the nurse shrubs. Shrub damage was highest at the higher grazing pressure. Correspondingly, browsing increased and survival decreased in saplings located inside the canopy of the shrubs at the high grazing pressure compared to the low grazing pressure. Saplings of both deciduous species showed a higher survival than the evergreens, while sapling browsing did not differ between species. The relative facilitation of sapling browsing and sapling survival - i.e. the difference between saplings inside and outside the shrub canopy - decreased at high grazing pressure as the facilitative species became less protective. Interestingly, these findings do not agree with current conceptual facilitation-stress models predicting increasing facilitation with abiotic stress. We used

  7. Eco-monitoring of highly contaminated areas: historic heavy metal contamination in tree ring records

    NASA Astrophysics Data System (ADS)

    Baross, Norbert; Jordán, Győző; Albert, Julianna; Abdaal, Ahmed; Anton, Attila

    2014-05-01

    This study examines and compares tree rings of trees grown in a mining area highly contaminated with heavy metals. Tree rings offers an excellent opportunity for eco-monitoring polluted areas. Contamination dispersion from the source to the receptors can be studied in time and space. The sampled area is located in the eastern part of the Matra Mts. of the Inner-Carpathian calc-alkaline Volcanic Arc (Hungary) with abundant historical ore (Pb, Zn, Cu, etc.) mining in the area. Dense forests are composed of the most typical association of the Turkey oak (Quercus cerris). Scots pine (Pinus sylvestris), European black pine (Pinus nigra), oak (Quercus robur), beech (Fagus sylvatica), and hornbeam (Carpinus betulus) also occurs in the landscape. Sampled trees are located within a 1km radius of the abandoned historic ore mines. Sample sites were located above the old mines and waste rock heaps, under the waste rock heaps and on the floodplain of the Ilona Creek. The sampled trees were selected by the following criteria: the tree should be healthy, showing no signs of thunderbolt or diseases and having a minimum diameter of 50 cm. Samples were taken with a tree borer at the height of 150 cm. At the same time, soil samples were also taken near the trees in a 25 cm depth. Prior to laboratory analysis, the samples measured and air dried. Every fifth years tree ring was taken from the samples under microscope, working backwards from the most recent outer ring (2012, the year of the sampling). Samples were digested with a mixture of H2SO4 and H2O2m in Teflon vessels in a microwave unit. The samples were analyzed by ICP-OES instrument. The results were evaluated with statistical method. Results revealed a consistent picture showing distinct locations and years of the contamination history in the former mining area. Some elements are built into the trees more efficiently than other elements depending on mobility in the soil solution that is influenced by soil chemical properties

  8. Influence of catchment vegetation on mercury accumulation in lake sediments from a long-term perspective.

    PubMed

    Rydberg, Johan; Rösch, Manfred; Heinz, Emanuel; Biester, Harald

    2015-12-15

    Organic matter (OM) cycling has a large impact on the cycling of mercury (Hg) in the environment. Hence, it is important to have a thorough understanding on how changes in, e.g., catchment vegetation - through its effect on OM cycling - affect the behavior of Hg. To test whether shifts in vegetation had an effect on Hg-transport to lakes we investigated a sediment record from Herrenwieser See (Southern Germany). This lake has a well-defined Holocene vegetation history: at ~8700years BP Corylus avellana (hazel) was replaced by Quercus robur (oak), which was replaced by Abies alba (fir) and Fagus sylvatica (beech) ~5700years BP). We were particularly interested in testing if coniferous vegetation leads to a larger export of Hg to aquatic systems than deciduous vegetation. When hazel was replaced by oak, reduced soil erosion and increased transport of DOM-bound mercury from the catchment resulted in increases in both Hg-concentrations and accumulation rates (61ngg(-1) and 5.5ngcm(-2)yr.(-)(1) to 118ngg(-1) and 8.5ngcm(-2)yr.(-)(1)). However, even if Hg-concentrations increased also in association with the introduction of fir and beech (173ngg(-1)), as a result of higher Hg:C, there was no increase in Hg-accumulation rates (7.6ngcm(-2)yr.(-)(1)), because of a decreased input of OM. At around 2500years BP Hg-accumulation rates and Hg-concentration indicated an additional input of Hg to the sediment (316ngg(-1) and 10.3ngcm(-2)yr.(-)(1)), which might be due to increased human activities in the area, e.g., forest burning or mining. Our results contrast those of several paired-catchment studies that suggest a higher release of Hg from coniferous than deciduous forest, and there is a need for studies with a long-term perspective to increase our understanding of the effects of slow and gradual processes on mercury cycling.

  9. Impact of anthropogenic induced nitrogen input and liming on phosphorous leaching in forest soils

    NASA Astrophysics Data System (ADS)

    Holzmann, Stefan; Puhlmann, Heike; Wilpert, Klaus

    2016-04-01

    Introduction: Phosphorous (P) is essential for sustainable forest growth, yet the impact of anthropogenic impacts on P leaching losses from forest soils are hardly known. Methods: We conducted an irrigation experiment with 128 mesocosms of 7.4 cm diameter containing 20 cm mineral soil plus the organic layer from three forest sites representing a gradient of resin extractable P of the A-horizon. On each site we selected a Fagus sylvatica and a Picea abies managed subsite. Half of the cylinders where planted with seedlings of the respective species to access the plant impact. We simulated ambient rain (AR), anthropogenic nitrogen input (NI) of 100 kg/ha/a and forest liming (FL) with a dolomite input of 0.3 Mg/ha/a. Soil solution was extracted from the organic layer and at 20 cm depth. We collected the soil solution over a period of 13.5 months and analyzed it separated by 5 periods. The soil solution was analyzed for total phosphorous (TP) by measuring the molybdane reactive phosphorous after acid digestion. To analyze the multivariate dataset we applied random forest modelling and used partial (co-)dependency plots to interpret the results. Results: The TP content of the soil solution from the organic horizon was approximately ten times higher than the soil solution content of the mineral soil. The NI treatment did increase the TP content on all sites. The increase was more pronounced in the organic layer than in the mineral layer. The FL treatment lead to a slight increase of TP in the organic layer while we could observe a slight decrease in the mineral horizon. Both the organic layer and the mineral horizon showed a seasonal cycle with the exception of one Picea abies subsite which displayed a constant increase in TP in the organic layer. The seasonal cycle of the organic horizon had a minimum during the period of April to July, while the minimum at the mineral horizon was during November to January. Conclusion: TP in the soil solution is highest in the organic

  10. Hydraulic properties of naturally regenerated beech saplings respond to canopy opening.

    PubMed

    Caquet, Blandine; Barigah, Têtè S; Cochard, Hervé; Montpied, Pierre; Collet, Catherine; Dreyer, Erwin; Epron, Daniel

    2009-11-01

    Enhanced sapling growth in advance regeneration requires gaps in the canopy, but is often delayed after canopy opening, because acclimation of saplings to the new environment is gradual and may last for several years. Canopy opening is expected to result in an increased transpiration because of a larger climatic demand and a higher stomatal conductance linked to the higher rates of photosynthesis. Therefore, we focused on the changes in water relations and the hydraulic properties of beech (Fagus sylvatica L.) saplings during 2 years after canopy opening. We tested the hypothesis that an increase in leaf-specific hydraulic conductance and a decrease in vulnerability to cavitation occur to sustain an enhanced transpiration. Hydraulic conductance of defoliated shoots, vulnerability to cavitation, size and density of xylem vessels as well as stomatal conductance were recorded on saplings growing in shade (S saplings) or in gaps created by opening the canopy (shade-to-light, SL saplings). Hydraulic conductance per unit cross-sectional area (K(AS)) did not differ in the shoots of S and SL saplings. But a higher ratio stem cross-sectional area/leaf area resulted in a higher leaf-specific hydraulic conductance of the shoots (K(AL)) of SL saplings. Contrary to expectations, vulnerability to cavitation increased transitorily in stems during the first year after canopy opening and no difference was observed between the two treatments in light-saturated stomatal conductance. During the second year, vulnerability to cavitation was similar in the S and SL saplings and light-saturated stomatal conductance increased in SL saplings. These results demonstrate a release of the hydraulic constraints after canopy opening with an adjustment of the ratio stem cross-sectional area/leaf area. But the larger vulnerability to cavitation during the first year could limit stomatal opening and therefore the ability of beech saplings to use the available light for photosynthesis and could

  11. Increased nitrate availability in the soil of a mixed mature temperate forest subjected to elevated CO2 concentration (canopy FACE)

    NASA Astrophysics Data System (ADS)

    Schleppi, Patrick; Inga, Bucher-Wallin; Frank, Hagedorn; Christian, Körner

    2013-04-01

    In a mature temperate forest in Hofstetten, Switzerland, deciduous tree canopies were subjected to a free-air CO2 enrichment (FACE) for a period of eight years. The effect of this treatment on the availability of nitrogen (N) in the soil was assessed along three transects across the experimental area, one under Fagus sylvatica, one under Quercus robur and Q. petraea and one under Carpinus betulus. Nitrate, ammonium and dissolved organic N (DON) were analysed in soil solution obtained with suction cups. Nitrate and ammonium were also captured in buried ion-exchange resin bags. These parameters were related to the local intensity of the FACE treatment as measured from the 13C depletion of dissolved inorganic carbon in the soil solution, because the CO2 used for the treatment was depleted in 13C (Schleppi et al., 2012). Over the eight years of the experiment, the CO2 enrichment reduced DON concentrations, did not affect ammonium, but induced higher nitrate concentrations, both in soil solution and in resin bags. In the nitrate captured in the resin bags, the natural abundance of the isotope 15N strongly increased. This indicates that the CO2 enrichment accelerated net nitrification, probably as an effect of the higher soil moisture resulting from the reduced transpiration of the CO2-enriched trees. It is also possible that N mineralisation was enhanced by root exudates (priming effect) or that the uptake of inorganic N by these trees decreased slightly as the result of a reduced N demand for fine root growth. In this mature deciduous forest we did not observe any progressive N limitation due to elevated atmospheric CO2 concentrations; on the contrary, we observed an enhanced N availability over the eight years of our measurements. This may, together with the global warming projected, exacerbate problems related to N saturation and nitrate leaching, although it is uncertain how long the observed trends will last in the future. Following the experiment with deciduous

  12. Reconstruction of full glacial environments and summer air temperatures from Lago della Costa, a refugial site in northeastern Italy.

    NASA Astrophysics Data System (ADS)

    Samartin, S. V.; Heiri, O.; Boltshauser-Kaltenrieder, P.; Tinner, W.

    2014-12-01

    Vegetation and climate during the Last Glacial Maximum (LGM) were considerably different than during the current interglacial (Holocene). In Europe large areas north of 40°N were entirely covered by continental ice-sheets and widespread permafrost, with temperatures around 10-20°C lower than at present, whereas further south aridity and temperatures 7-10°C cooler than today occurred. Cool climatic conditions and growing ice-sheets during the LGM radically reduced forest extent and diversity in Europe to a restricted number of so-called "refugia", mostly located in the southern part of the continent. The Euganian Hills in northeastern Italy are supposed to be one of the northernmost refugia of thermophilous mixed oak forest species (e.g. deciduous Quercus, Tilia, Ulmus, Fraxinus excelsior, Acer, Carpinus, Castanea) as well of some temperate mesophilous species (e.g. Fagus sylvatica, Abies alba) in Europe. In this study we present the first European chironomid-based quantitative temperature reconstruction for the LGM and address the question whether climate conditions were warm enough to permit the local survival of Quercetum mixtum species between ca. 31'000-17'000 cal yr BP. Chironomids preserved in a lake sediment core from Lago della Costa (7m a.s.l.), a lake on the border of the Euganean Hills in northeastern Italy, allowed quantitative reconstruction of Full and Late Glacial July air temperatures using a combined Swiss-Norwegian temperature inference model based on chironomid assemblages from 274 lakes. Our results suggest that July air temperatures never fell below 10°C which are considered necessary for forest growth. In general, mild climatic conditions prevailed between ca. 31'000-17'000 cal yr BP with temperatures ranging from ca. 11°C to 15.7°C. The expansion of thermophilous trees such as Quercus, Tilia, Ulmus, Fraxinus excelsior, Acer, Carpinus, Castanea (Quercetum mixtum) between ca. 30'000-23'000 cal yr BP can most likely be explained by climate

  13. Aphid infestation affecting the biogeochemistry of European beech saplings

    NASA Astrophysics Data System (ADS)

    Michalzik, B.; Levia, D. F., Jr.; Bischoff, S.; Näthe, K.

    2014-12-01

    Mass outbreaks of herbivore insects are known to perturb the functional properties of forests. However, it is less clear how endemic to moderate aboveground herbivory affects the vertical flow of nutrients from tree canopies to the soil. Here, we report on the effects of low to moderate infestation levels of the woolly beech aphid (Phyllaphis fagi L.) on the nutrient dynamics and hydrology of European beech (Fagus sylvatica L.). In a potted sapling experiment, we followed the vertical dynamics of nutrients via throughfall (TF), stemflow (SF) and litter leachates (LL) collected over ten weeks underneath infested and uninfested control trees. Aphid infestation amplifies the fluxes of K+, Mn2+ and particulate nitrogen (0.45μm < PN < 500 μm) in TF solution by 42% for K+, 59% for Mn2+ and 13% for PN relative to the control. In contrast, fluxes of NH4-N and SO4-S diminished during peaking aphid abundance by 26 and 16%, respectively. Differences in canopy-derived dissolved nitrogen and carbon compounds, sulfur (S), Ca2+, Mg2+, Na+ were < 10%. The effect of aphid abundance on nutrient dynamics was most notable in TF and SF and diminished in LL.Aphid infestation greatly altered the SF fluxes of DOC, K+, Mn2+, DON and sulfur-species, which were significantly concentrated at the tree base by "funneling" the rainfall through the canopy biomass to the trunk. Normalized to one square meter, water and nutrient fluxes were amplified by a factor of up to 200 compared to TF.Imaging of leaf surfaces by scanning electron microscopy exhibited notable differences of the surface morphology and microbiology of control, lightly infested, and heavily infested leaves. This observation might point to an aphid-mediated alteration of the phyllosphere ecology triggering the microbial uptake of NH4-N and SO4-S and its transformation to particulate N by magnified biomass growth of the phyllosphere microflora, consequently changing the chemical partitioning and temporal availability of nitrogen.

  14. Tree ring isotopes of beech and spruce in response to short-term climate variability across Central European sites: Common and contrasting physiological mechanisms

    NASA Astrophysics Data System (ADS)

    Weigt, Rosemarie; Klesse, Stefan; Treydte, Kerstin; Frank, David; Saurer, Matthias; Siegwolf, Rolf T. W.

    2016-04-01

    The combined study of tree-ring width and stable C and O isotopes provides insight in the coherences between carbon allocation during stem growth and the preceding conditions of gas exchange and formation of photosynthates as all influenced by environmental variation. In this large-scale study comprising 10 sites across a range of climate gradients (temperature, precipitation) throughout Central Europe, we investigated tree-rings in European beech (Fagus sylvatica) and Norway spruce (Picea abies) trees. The sampling design included larger and smaller trees. The short-term, i.e. year-to-year, variability in the isotope time series over 100 yrs was analyzed in relation to tree-ring growth and climate variation. The generally strong correlation between the year-to-year differences in δ13C (corrected for the atmospheric shift due to 13C-depleted CO2 from fossil combustion) and δ18O across most sites emphasized the role of stomatal conductance in controlling leaf gas exchange. However, the correlation between both isotopes decreased during some periods. At several sites this reduction in correlation was particularly pronounced during recent decades. This suggests a decoupling between stomatal and photosynthetic responses to environmental conditions on the one hand, and carbon allocation to stem tissue on the other hand. Variability in the isotopic ratio largely responded to summer climate, but was weakly correlated to annual stem growth. In contrast, climate sensitivity of radial growth in both species was rather site-dependent, and was strongest at the driest (in terms of soil water capacity) site. We will also present results of isotope responses with respect to extreme climate events. Understanding the underlying physiological mechanisms controlling the short-term variation in tree-ring signals will help to assess and more precisely constrain the possible range of growth performance of these ecologically and economically important tree species under future climate

  15. Holocene variability in the range distribution and abundance of Pinus, Picea abies, and Quercus in Romania; implications for their current status

    NASA Astrophysics Data System (ADS)

    Feurdean, Angelica; Tanţău, Ioan; Fărcaş, Sorina

    2011-10-01

    have been spatially constrained, as populations below ca 1000 m were replaced by Fagus sylvatica from ca 4000 years ago, Recently, Pinus (mainly P. sylvestris) and P. abies have both experienced range expansions a consequence of forest management. Quercus is the only continental deciduous tree that has maintained high abundance throughout the whole Holocene. Members of this genus demonstrated high resilience to climate change and disturbance; following a period of decline it was capable of recovery during subsequent intervals of warm conditions or disturbance.

  16. An epidemiological assessment of stomatal ozone flux-based critical levels for visible ozone injury in Southern European forests.

    PubMed

    Sicard, Pierre; De Marco, Alessandra; Dalstein-Richier, Laurence; Tagliaferro, Francesco; Renou, Camille; Paoletti, Elena

    2016-01-15

    Southern forests are at the highest ozone (O3) risk in Europe where ground-level O3 is a pressing sanitary problem for ecosystem health. Exposure-based standards for protecting vegetation are not representative of actual field conditions. A biologically-sound stomatal flux-based standard has been proposed, although critical levels for protection still need to be validated. This innovative epidemiological assessment of forest responses to O3 was carried out in 54 plots in Southeastern France and Northwestern Italy in 2012 and 2013. Three O3 indices, namely the accumulated exposure AOT40, and the accumulated stomatal flux with and without an hourly threshold of uptake (POD1 and POD0) were compared. Stomatal O3 fluxes were modeled (DO3SE) and correlated to measured forest-response indicators, i.e. crown defoliation, crown discoloration and visible foliar O3 injury. Soil water content, a key variable affecting the severity of visible foliar O3 injury, was included in DO3SE. Based on flux-effect relationships, we developed species-specific flux-based critical levels (CLef) for forest protection against visible O3 injury. For O3 sensitive conifers, CLef of 19 mmol m(-2) for Pinus cembra (high O3 sensitivity) and 32 mmol m(-2) for Pinus halepensis (moderate O3 sensitivity) were calculated. For broadleaved species, we obtained a CLef of 25 mmol m(-2) for Fagus sylvatica (moderate O3 sensitivity) and of 19 mmol m(-2) for Fraxinus excelsior (high O3 sensitivity). We showed that an assessment based on PODY and on real plant symptoms is more appropriated than the concentration-based method. Indeed, POD0 was better correlated with visible foliar O3 injury than AOT40, whereas AOT40 was better correlated with crown discoloration and defoliation (aspecific indicators). To avoid an underestimation of the real O3 uptake, we recommend the use of POD0 calculated for hours with a non-null global radiation over the 24-h O3 accumulation window.

  17. Nitrogen Addition Enhances Drought Sensitivity of Young Deciduous Tree Species

    PubMed Central

    Dziedek, Christoph; Härdtle, Werner; von Oheimb, Goddert; Fichtner, Andreas

    2016-01-01

    Understanding how trees respond to global change drivers is central to predict changes in forest structure and functions. Although there is evidence on the mode of nitrogen (N) and drought (D) effects on tree growth, our understanding of the interplay of these factors is still limited. Simultaneously, as mixtures are expected to be less sensitive to global change as compared to monocultures, we aimed to investigate the combined effects of N addition and D on the productivity of three tree species (Fagus sylvatica, Quercus petraea, Pseudotsuga menziesii) in relation to functional diverse species mixtures using data from a 4-year field experiment in Northwest Germany. Here we show that species mixing can mitigate the negative effects of combined N fertilization and D events, but the community response is mainly driven by the combination of certain traits rather than the tree species richness of a community. For beech, we found that negative effects of D on growth rates were amplified by N fertilization (i.e., combined treatment effects were non-additive), while for oak and fir, the simultaneous effects of N and D were additive. Beech and oak were identified as most sensitive to combined N+D effects with a strong size-dependency observed for beech, suggesting that the negative impact of N+D becomes stronger with time as beech grows larger. As a consequence, the net biodiversity effect declined at the community level, which can be mainly assigned to a distinct loss of complementarity in beech-oak mixtures. This pattern, however, was not evident in the other species-mixtures, indicating that neighborhood composition (i.e., trait combination), but not tree species richness mediated the relationship between tree diversity and treatment effects on tree growth. Our findings point to the importance of the qualitative role (‘trait portfolio’) that biodiversity play in determining resistance of diverse tree communities to environmental changes. As such, they provide

  18. Intraspecific Variation in Wood Anatomical, Hydraulic, and Foliar Traits in Ten European Beech Provenances Differing in Growth Yield

    PubMed Central

    Hajek, Peter; Kurjak, Daniel; von Wühlisch, Georg; Delzon, Sylvain; Schuldt, Bernhard

    2016-01-01

    In angiosperms, many studies have described the inter-specific variability of hydraulic-related traits and little is known at the intra-specific level. This information is however mandatory to assess the adaptive capacities of tree populations in the context of increasing drought frequency and severity. Ten 20-year old European beech (Fagus sylvatica L.) provenances representing the entire distribution range throughout Europe and differing significantly in aboveground biomass increment (ABI) by a factor of up to four were investigated for branch wood anatomical, hydraulic, and foliar traits in a provenance trial located in Northern Europe. We quantified to which extend xylem hydraulic and leaf traits are under genetic control and tested whether the xylem hydraulic properties (hydraulic efficiency and safety) trades off with yield and wood anatomical and leaf traits. Our results showed that only three out of 22 investigated ecophysiological traits showed significant genetic differentiations between provenances, namely vessel density (VD), the xylem pressure causing 88% loss of hydraulic conductance and mean leaf size. Depending of the ecophysiological traits measured, genetic differentiation between populations explained 0–14% of total phenotypic variation, while intra-population variability was higher than inter-population variability. Most wood anatomical traits and some foliar traits were additionally related to the climate of provenance origin. The lumen to sapwood area ratio, vessel diameter, theoretical specific conductivity and theoretical leaf-specific conductivity as well as the C:N-ratio increased with climatic aridity at the place of origin while the carbon isotope signature (δ13C) decreased. Contrary to our assumption, none of the wood anatomical traits were related to embolism resistance but were strong determinants of hydraulic efficiency. Although ABI was associated with both VD and δ13C, both hydraulic efficiency and embolism resistance were

  19. Spatial variation in springtime food resources influences the winter body mass of roe deer fawns.

    PubMed

    Pettorelli, Nathalie; Dray, Stephane; Gaillard, Jean-Michel; Chessel, Daniel; Duncan, Patrick; Illius, Andrew; Guillon, Nadine; Klein, Francois; Van Laere, Guy

    2003-11-01

    .g. butcher's broom ( Ruscus aculeatus) and beech ( Fagus sylvatica)], was negatively related to fawn body mass. We conclude that the spatial variation in the body mass of fawns in winter in this forest is as important as the temporal variation, and that the distribution of plant species that are actively selected during spring and summer is an important determinant of spatial variation in winter fawn body mass. The availability of these plants is therefore likely to be a key factor in the dynamics of roe deer populations.

  20. Forest Management Type Influences Diversity and Community Composition of Soil Fungi across Temperate Forest Ecosystems

    PubMed Central

    Goldmann, Kezia; Schöning, Ingo; Buscot, François; Wubet, Tesfaye

    2015-01-01

    Fungal communities have been shown to be highly sensitive toward shifts in plant diversity and species composition in forest ecosystems. However, little is known about the impact of forest management on fungal diversity and community composition of geographically separated sites. This study examined the effects of four different forest management types on soil fungal communities. These forest management types include age class forests of young managed beech (Fagus sylvatica L.), with beech stands age of approximately 30 years, age class beech stands with an age of approximately 70 years, unmanaged beech stands, and coniferous stands dominated by either pine (Pinus sylvestris L.) or spruce (Picea abies Karst.) which are located in three study sites across Germany. Soil were sampled from 48 study plots and we employed fungal ITS rDNA pyrotag sequencing to assess the soil fungal diversity and community structure. We found that forest management type significantly affects the Shannon diversity of soil fungi and a significant interaction effect of study site and forest management on the fungal operational taxonomic units richness. Consequently distinct fungal communities were detected in the three study sites and within the four forest management types, which were mainly related to the main tree species. Further analysis of the contribution of soil properties revealed that C/N ratio being the most important factor in all the three study sites whereas soil pH was significantly related to the fungal community in two study sites. Functional assignment of the fungal communities indicated that 38% of the observed communities were Ectomycorrhizal fungi (ECM) and their distribution is significantly influenced by the forest management. Soil pH and C/N ratio were found to be the main drivers of the ECM fungal community composition. Additional fungal community similarity analysis revealed the presence of study site and management type specific ECM genera. This study extends our

  1. Long-term exposure to twice-ambient ozone (O3) affects carbon sink strength, allocation and stem growth in adult central European forest trees

    NASA Astrophysics Data System (ADS)

    Grams, T. E.; Matyssek, R.

    2009-12-01

    Amongst air pollutants, ground-level ozone (O3) is potentially the most detrimental to vegetation. Spreading globally, enhanced O3 levels are predicted to increase, in particular, in rapidly developing countries and, thus, O3 must now be considered in climate change scenarios and post-Kyoto policies. Here, we present an appraisal of a unique 8-year free-air O3 fumigation experiment on adult European beech (Fagus sylvatica) and Noway spruce (Picea abies), ecologically and economically important, late-succession tree species in Central Europe. For the first time, whole-plant canopies of naturally grown, 60 to 70 years old forest trees were exposed to twice-ambient O3 levels for a total of eight years. Throughout the study period, enhanced O3 uptake in the elevated O3 treatment affected net C fixation and distinctly weakened the whole-stem growth in beech. In contrast, adult spruce at the same site did not display decline in stem biomass development. Those findings corroborate species-specific sensitivities to O3 reported from previous chamber studies on juvenile beech and spruce trees. Carbon allocation of adult trees, as a mechanistical basis of growth processes, was investigated through stable isotope tracer experiments using 13C depleted CO2 at the canopy level. To this end, a novel free-air CO2 exposure system, named tubeFACE, was developed, which employed micro-porous PVC tubes hanging through the canopy of adult trees. In a 19-day 13CO2/12CO2 labeling experiment, CO2 with a δ13C of -46.9 ‰ was continuously released into the canopy to increase [CO2] by 100 µmol mol-1, resulting in a reduction in δ13C of about 8 ‰. Subsequently, C allocation to respiratory pools of various tree organs was studied. Similar to the reduced stem growth in beech, elevated O3 significantly reduced allocation of labeled C to stem respiration, whereas in spruce such a reduction was not found. Hence, our study underlines the need to understand O3 risks by species, so that modeling

  2. Wild vascular plants gathered for consumption in the Polish countryside: a review

    PubMed Central

    Łuczaj, Łukasz; Szymański, Wojciech M

    2007-01-01

    Background This paper is an ethnobotanical review of wild edible plants gathered for consumption from the end of the 18th century to the present day, within the present borders of Poland. Methods 42 ethnographic and botanical sources documenting the culinary use of wild plants were analyzed. Results The use of 112 species (3.7% of the flora) has been recorded. Only half of them have been used since the 1960s. Three species: Cirsium rivulare, Euphorbia peplus and Scirpus sylvaticus have never before been reported as edible by ethnobotanical literature. The list of wild edible plants which are still commonly gathered includes only two green vegetables (Rumex acetosa leaves for soups and Oxalis acetosella as children's snack), 15 folk species of fruits and seeds (Crataegus spp., Corylus avellana, Fagus sylvatica, Fragaria vesca, Malus domestica, Prunus spinosa, Pyrus spp., Rosa canina, Rubus idaeus, Rubus sect. Rubus, Sambucus nigra, Vaccinium myrtillus, V. oxycoccos, V. uliginosum, V. vitis-idaea) and four taxa used for seasoning or as preservatives (Armoracia rusticana root and leaves, Carum carvi seeds, Juniperus communis pseudo-fruits and Quercus spp. leaves). The use of other species is either forgotten or very rare. In the past, several species were used for food in times of scarcity, most commonly Chenopodium album, Urtica dioica, U. urens, Elymus repens, Oxalis acetosella and Cirsium spp., but now the use of wild plants is mainly restricted to raw consumption or making juices, jams, wines and other preserves. The history of the gradual disappearance of the original barszcz, Heracleum sphondylium soup, from Polish cuisine has been researched in detail and two, previously unpublished, instances of its use in the 20th century have been found in the Carpathians. An increase in the culinary use of some wild plants due to media publications can be observed. Conclusion Poland can be characterized as a country where the traditions of culinary use of wild plants became

  3. Towards a strontium isoscape for the determination of provenance of prehistoric wooden findings

    NASA Astrophysics Data System (ADS)

    Horsky, Monika; Tintner, Johannes; Bolka, Monika; Grabner, Michael; Kowarik, Kerstin; Reschreiter, Hans; Kern, Anton; Horacek, Micha; Prohaska, Thomas

    2014-05-01

    Prehistoric wood artefacts have been excavated from ancient salt mine galleries in Hallstatt, Austria. These findings present a unique archive of information on Bronze and Iron Age mining and trade relations, as for certain tools a production elsewhere and transport to the mine is assumed. These wooden artefacts contain the geochemical information of their growth location, though masked by secondary salts due to the storage conditions. Consequently, the analysis of the biogenic 87Sr/86Sr isotope ratios of the findings was carried out in comparison to the respective signatures of trees from possible regions of origin, in order to draw conclusions on prehistoric trade routes. Thus - in addition to Hallstatt - seven regions in the Alpine region of Austria as well as in the Northern and Southern lowlands were selected based on known settlements in the time period of interest. Within all regions, the geological bedrock variability was considered for the definition of sampling spots, which resulted in a total of 26 locations. Four tree species represented in the archaeological finds (i.e. Picea abies, Abies alba, Fagus sylvatica and Quercus sp.) were sampled upon availability. Wood sample digests from eight replicate trees per location were analysed using multicollector-inductively coupled plasma-mass spectrometry (MC-ICP-MS). In order to reveal the biogenic signatures of the prehistoric findings, a decontamination method based on acid leaching was developed. We could successfully separate biogenic from secondary Sr and adopted a mixing theory to account for possibly incomplete removal of the latter. The Sr isotope ratio data obtained from modern trees (i.e. bioavailable Sr) reflect the geological heterogeneity of the Alps, which challenges the creation of an isoscape and its applicability to distinct provenance determination. Different geologic bedrock types can be clearly distinguished by their 87Sr/86Sr, e.g. marine sedimentary and igneous rocks. Furthermore, the data

  4. Carbon flux to woody tissues in a beech/spruce forest during summer and in response to chronic O3 exposure

    NASA Astrophysics Data System (ADS)

    Ritter, W.; Andersen, C. P.; Matyssek, R.; Grams, T. E. E.

    2011-11-01

    The present study compares the dynamics in carbon (C) allocation of adult deciduous beech (Fagus sylvatica) and evergreen spruce (Picea abies) during summer and in response to seven-year-long exposure with twice-ambient ozone (O3) concentrations (2 × O3). Focus was on the respiratory turn-over and translocation of recent photosynthates at various positions along the stems, coarse roots and soils. The hypotheses tested were that (1) 2 × O3 decreases the allocation of recent photosynthates to CO2 efflux of stems and coarse roots of adult trees, and that (2) according to their different O3 sensitivities this effect is stronger in beech than in spruce. Labeling of whole tree canopies was applied by releasing 13C depleted CO2 (δ13C of -46.9‰) using a free-air stable carbon isotope approach. Canopy air δ13C was reduced for about 2.5 weeks by ca. 8‰ in beech and 6‰ in spruce while the increase in CO2 concentration was limited to about 110 μl l-1 and 80 μl l-1, respectively. At the end of the labeling period, δ13C of stem CO2 efflux and phloem sugars was reduced to a similar extend by ca. 3-4‰ (beech) and ca. 2-3‰ (spruce). The fraction of labeled C (fE,new) in stem CO2 efflux amounted to 0.3 to 0.4, indicating slow C turnover of the respiratory supply system in both species. Elevated O3 slightly stimulated the allocation of recently fixed photosynthates to stem and coarse root respiration in spruce (rejection of hypothesis I for spruce), but resulted in a significant reduction in C flux in beech (acceptance of hypotheses I and II). The distinct decrease in C allocation to beech stems indicates the potential of chronic O3 stress to substantially mitigate the C sink strength of trees on the long-term scale.

  5. Measurement and modelling of sap flow in maize plants

    NASA Astrophysics Data System (ADS)

    Heinlein, Florian; Biernath, Christian; Hoffmann, Peter; Klein, Christian; Thieme, Christoph; Priesack, Eckart

    2014-05-01

    Climate change as well as the changing composition of the atmosphere will have an impact on future yield of agricultural plants. In order to better estimate these impacts new, mechanistic plant growth models are needed. These models should be able to dynamically reproduce the plants' reactions to modified climate state variables like temperature, atmospheric CO2-concentration and water availability. In particular, to better describe the crop response to more strongly changing water availability the simulation of plant-internal water and solute transport processes in xylem and phloem needs to be improved. Our existing water transport model consists of two coupled 1-D Richards equations to calculate water transport in the soil and in the plants. This model has already been successfully applied to single Fagus sylvatica L. trees. At present it is adapted to agricultural plants such as maize. To simulate the water transport within the plants a representation of the flow paths, i.e. the plant architecture, is required. Aboveground plant structures are obtained from terrestrial laser scan (TLS) measurements at different development stages. These TLSs have been executed at the lysimeter facilities of Helmholtz Zentrum München and at the TERENO (Terrestrial Environmental Observatories) research farm Scheyern. Additionally, an L-system model is used to simulate aboveground and belowground plant architectures. In a further step, the quality of the explicit water flow model has to be tested using measurements. The Heat-Ratio-Method has been employed to directly measure sap flow in larger maize plants during a two-months-period in summer 2013 with a resolution of 10 minutes and thus, the plants' transpiration can be assessed. Water losses from the soil are determined by measuring the weight of lysimeters. From this evapotranspiration can be calculated. Transpiration and evapotranspiration are also simulated by application of the modelling system Expert-N. This framework

  6. Carbon flux to woody tissues in a beech/spruce forest during summer and in response to chronic elevated O3 exposure

    NASA Astrophysics Data System (ADS)

    Ritter, W.; Andersen, C. P.; Matyssek, R.; Grams, T. E. E.

    2011-04-01

    The present study compares the dynamics in carbon (C) allocation of adult deciduous beech (Fagus sylvatica) and evergreen spruce (Picea abies) during summer and in response to seven-year-long exposure with twice-ambient ozone (O3) concentrations (2 × O3). Focus was on the respiratory turn-over and translocation of recent photosynthates at various positions along the stems, coarse roots and soils. The hypotheses tested were that (1) 2 × O3 decreases the allocation of recent photosynthates to CO2 efflux of stems and coarse roots of adult trees, and that (2) according to their different O3 sensitivities this effect is stronger in beech than in spruce. Labeling of whole tree canopies was applied by releasing 13C depleted CO2 (δ13C of -46.9‰) using a free-air stable carbon isotope approach. Canopy air δ13C was reduced for about 2.5 weeks by ca. 8‰ in beech and 6‰ in spruce while the increase in CO2 concentration was limited to about 110 μL L-1 and 80 μL L-1, respectively. At the end of the labeling period, δ13C of stem CO2 efflux and phloem sugars was reduced to a similar extend by ca. 3-4‰ (beech) and ca. 2-3‰ (spruce). The fraction of labeled C (fE,new) in stem CO2 efflux amounted to 0.3 to 0.4, indicating slow C turnover of the respiratory supply system in both species. Elevated O3 slightly stimulated the allocation of recently fixed photosynthates to stem and coarse root respiration in spruce (rejection of hypothesis I for spruce), but resulted in a significant reduction in C flux in beech (acceptance of hypotheses I and II). The distinct decreased in C allocation to beech stems indicates the potential of chronic O3 stress to substantially mitigate the C sink strength of trees on the long-term scale.

  7. Woody plant richness and NDVI response to drought events in Catalonian (northeastern Spain) forests.

    PubMed

    Lloret, F; Lobo, A; Estevan, H; Maisongrande, P; Vayreda, J; Terradas, J

    2007-09-01

    The role of species diversity on ecosystem resistance in the face of strong environmental fluctuations has been addressed from both theoretical and experimental viewpoints to reveal a variety of positive and negative relationships. Here we explore empirically the relationship between the richness of forest woody species and canopy resistance to extreme drought episodes. We compare richness data from an extensive forest inventory to a temporal series of satellite imagery that estimated drought impact on forest canopy as NDVI (normalized difference vegetation index) anomalies of the dry summer in 2003 in relation to records of previous years. We considered five different types of forests that are representative of the main climatic and altitudinal gradients of the region, ranging from lowland Mediterranean to mountain boreal-temperate climates. The observed relationship differed among forest types and interacted with the climate, summarised by the Thorntwaite index. In Mediterranean Pinus halepensis forests, NDVI decreased during the drought. This decrease was stronger in forests with lower richness. In Mediterranean evergreen forests of Quercus ilex, drought did not result in an overall NDVI loss, but lower NDVI values were observed in drier localities with lower richness, and in more moist localities with higher number of species. In mountain Pinus sylvestris forests NDVI decreased, mostly due to the drought impact on drier localities, while no relation to species richness was observed. In moist Fagus sylvatica forests, NDVI only decreased in plots with high richness. No effect of drought was observed in the high mountain Pinus uncinata forests. Our results show that a shift on the diversity-stability relationship appears across the regional, climatic gradient. A positive relationship appears in drier localities, supporting a null model where the probability of finding a species able to cope with drier conditions increases with the number of species. However, in

  8. Contrasting distribution and seasonal dynamics of carbohydrate reserves in stem wood of adult ring-porous sessile oak and diffuse-porous beech trees.

    PubMed

    Barbaroux, C; Bréda, N

    2002-12-01

    We tested the hypothesis that broad-leaved forest species with contrasting wood anatomy and hydraulic system (ring-porous versus diffuse-porous) also differ in distribution and seasonal dynamics of carbohydrate reserves in stem wood. Total nonstructural carbohydrate (TNC) reserves (starch and sugars) were measured enzymatically in the 10 youngest stem xylem rings of adult oak (Quercus petraea (Matt.) Liebl.) and beech (Fagus sylvatica L.) trees during an annual cycle. Radial distribution of carbohydrates was investigated according to ring age. On all dates, oak trees had twofold higher TNC concentration than beech trees (41 versus 23 mg g(DM)(-1)), with starch accounting for the high TNC concentration in oak. Seasonal dynamics of TNC concentration were significantly (P < 0.05) more pronounced in oak (20-64 mg TNC g(DM)(-1)) than in beech (17-34 mg TNC g(DM)(-1)). A marked decrease in TNC concentration was observed in oak trees during bud burst and early wood growth, whereas seasonal fluctuations in TNC concentrations in beech trees were small. The radial distribution of TNC based on ring age differed between species: TNC was restricted to the sapwood rings in oak, whereas in beech, it was distributed throughout the wood from the outermost sapwood ring to the pith. Although the high TNC concentrations in the outermost rings accounted for most of the observed seasonal pattern, all of the 10 youngest xylem rings analyzed participated in the seasonal dynamics of TNC in beech trees. The innermost sapwood rings of oak trees had low TNC concentrations. Stem growth and accumulation of carbon reserves occurred concomitantly during the first part of the season, when there was no soil water deficit. When soil water content was depleted, stem growth ceased in both species, whereas TNC accumulation was negligibly affected and continued until leaf fall. The contrasting dynamics and distribution of carbohydrate reserves in oak and beech are discussed with reference to differences

  9. A kinetic model relating the leaf uptake of carbonyl sulfide (COS) to water and CO2 fluxes and 13C fractionation

    NASA Astrophysics Data System (ADS)

    Seibt, Ulrike; Berry, Joe; Sandoval-Soto, Lisseth; Kuhn, Uwe; Kesselmeier, Jürgen

    2010-05-01

    Carbonyl sulfide (COS) is an atmospheric trace gas that holds great promise for studies of terrestrial carbon and water exchange. During photosynthesis, COS and CO2 follow the same pathway and are both taken up in enzyme reactions in leaves. We have developed a simple model of leaf COS uptake, analogous to the equations for CO2 and water fluxes. Leaf COS uptake predicted from the new equation was in good agreement with data from field and laboratory chambers, although with large uncertainties. We also obtained first estimates for the ratio of conductances of COS and water vapour. Empirically derived estimates were 2.0 ± 0.3 for laboratory data on Fagus sylvatica and 2.2 ± 0.8 for field data on Quercus agrifolia, both close to the theoretical estimate of 2.0 ± 0.2. As a consequence of the close coupling of leaf COS and CO2 uptake, the normalized uptake ratio of COS and CO2 can be used to provide estimates of Ci-Ca, the ratio of intercellular to atmospheric CO2, an important plant gas exchange parameter that cannot be measured directly. Published normalized COS to CO2 uptake ratios for leaf studies on a variety of species fall in the range of 1.5 to 4, corresponding to Ci-Ca ratios of 0.5 to 0.8. In addition, we utilize the coupling of Ci-Ca and photosynthetic 13C discrimination to derive an estimate of 2.8 ± 0.3 for the global mean normalized uptake ratio. This corresponds to a global vegetation sink of COS in the order of 900 ± 100 Gg S yr-1. Similarly, COS and 13C discrimination can be combined to obtain independent estimates of photosynthesis (GPP). The new process-oriented description provides a framework for understanding COS fluxes that should improve the usefulness of atmospheric COS data to obtain estimates of gross photosynthesis and stomatal conductance at regional to global scales.

  10. Future tendencies of climate indicators important for adaptation and mitigation strategies in forestry

    NASA Astrophysics Data System (ADS)

    Galos, Borbala; Hänsler, Andreas; Gulyas, Krisztina; Bidlo, Andras; Czimber, Kornel

    2014-05-01

    Climate change is expected to have severe impacts in the forestry sector, especially in low-elevation regions in Southeast Europe, where forests are vulnerable and sensitive to the increasing probability and severity of climatic extremes, especially to droughts. For providing information about the most important regional and local risks and mitigation options for the Carpathian basin, a GIS-supported Decision Support System is under development. This study focuses on the future tendencies of climate indicators that determine the distribution, growth, health status and production of forests as well as the potential pests and diseases. For the analyses the climate database of the Decision Support System has been applied, which contains daily time series for precipitation and temperature means and extremes as well as derived climate indices for 1961-2100. For the future time period, simulation results of 12 regional climate models are included (www.ensembles-eu.org) based on the A1B emission scenario. The main results can be summarized as follows: · The projected change of the climate indices (e.g. total number of hot days, frost days, dry days, consecutive dry periods) and forestry indices (e.g. Ellenberg climate quotient, Forestry aridity index; Tolerance index for beech) indicates the warming and drying of the growing season towards the end of the 21st century. These can have severe consequences on the ecosystem services of forests. · The climatic suitable area of the native tree species is projected to move northwards and upwards in the mountains, respectively. For beech (Fagus sylvatica L.) this shift would mean the drastic shrink of the distribution area in the analyzed region. · The characteristic climate conditions that are expected in the Carpathian basin in the second half of the century, are now located southeastern from the case study region. In this way, the potential future provenance regions can be determined. Results provide input for the climate

  11. Strong Coupling of Shoot Assimilation and Soil Respiration during Drought and Recovery Periods in Beech As Indicated by Natural Abundance δ13C Measurements

    PubMed Central

    Blessing, Carola H.; Barthel, Matti; Gentsch, Lydia; Buchmann, Nina

    2016-01-01

    Drought down-regulates above- and belowground carbon fluxes, however, the resilience of trees to drought will also depend on the speed and magnitude of recovery of these above- and belowground fluxes after re-wetting. Carbon isotope composition of above- and belowground carbon fluxes at natural abundance provides a methodological approach to study the coupling between photosynthesis and soil respiration (SR) under conditions (such as drought) that influence photosynthetic carbon isotope discrimination. In turn, the direct supply of root respiration with recent photoassimilates will impact on the carbon isotope composition of soil-respired CO2. We independently measured shoot and soil CO2 fluxes of beech saplings (Fagus sylvatica L.) and their respective δ13C continuously with laser spectroscopy at natural abundance. We quantified the speed of recovery of drought stressed trees after re-watering and traced photosynthetic carbon isotope signal in the carbon isotope composition of soil-respired CO2. Stomatal conductance responded strongly to the moderate drought (-65%), induced by reduced soil moisture content as well as increased vapor pressure deficit. Simultaneously, carbon isotope discrimination decreased by 8‰, which in turn caused a significant increase in δ13C of recent metabolites (1.5–2.5‰) and in δ13C of SR (1–1.5‰). Generally, shoot and soil CO2 fluxes and their δ13C were in alignment during drought and subsequent stress release, clearly demonstrating a permanent dependence of root respiration on recently fixed photoassimilates, rather than on older reserves. After re-watering, the drought signal persisted longer in δ13C of the water soluble fraction that integrates multiple metabolites (soluble sugars, amino acids, organic acids) than in the neutral fraction which represents most recently assimilated sugars or in the δ13C of SR. Nevertheless, full recovery of all aboveground physiological variables was reached within 4 days – and within 7

  12. Interactions between leaf nitrogen status and longevity in relation to N cycling in three contrasting European forest canopies

    NASA Astrophysics Data System (ADS)

    Wang, L.; Ibrom, A.; Korhonen, J. F. J.; Arnoud Frumau, K. F.; Wu, J.; Pihlatie, M.; Schjoerring, J. K.

    2013-02-01

    Seasonal and spatial variations in foliar nitrogen (N) parameters were investigated in three European forests with different tree species, viz. beech (Fagus sylvatica L.), Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) and Scots pine (Pinus sylvestris L.) growing in Denmark, the Netherlands and Finland, respectively. The objectives were to investigate the distribution of N pools within the canopies of the different forests and to relate this distribution to factors and plant strategies controlling leaf development throughout the seasonal course of a vegetation period. Leaf N pools generally showed much higher seasonal and vertical variability in beech than in the coniferous canopies. However, also the two coniferous tree species behaved very differently with respect to peak summer canopy N content and N re-translocation efficiency, showing that generalisations on tree internal vs. ecosystem internal N cycling cannot be made on the basis of the leaf duration alone. During phases of intensive N turnover in spring and autumn, the NH4+ concentration in beech leaves rose considerably, while fully developed green beech leaves had relatively low tissue NH4+, similar to the steadily low levels in Douglas fir and, particularly, in Scots pine. The ratio between bulk foliar concentrations of NH4+ and H+, which is an indicator of the NH3 emission potential, reflected differences in foliage N concentration, with beech having the highest values followed by Douglas fir and Scots pine. Irrespectively of the leaf habit, i.e. deciduous versus evergreen, the majority of the canopy foliage N was retained within the trees. This was accomplished through an effective N re-translocation (beech), higher foliage longevity (fir) or both (boreal pine forest). In combination with data from a literature review, a general relationship of decreasing N re-translocation efficiency with the time needed for canopy renewal was deduced, showing that leaves which live longer re

  13. Anatomical basis of the change in leaf mass per area and nitrogen investment with relative irradiance within the canopy of eight temperate tree species

    NASA Astrophysics Data System (ADS)

    Aranda, I.; Pardo, F.; Gil, L.; Pardos, J. A.

    2004-05-01

    Changes in leaf mass per area (LMA), nitrogen content on a mass-basis (N m) and on an area basis (N a) with relative irradiance were assessed in leaves of eight temperate species harvested at different depths in a canopy. Relative irradiance (GSF) at the points of leaf sampling was estimated by hemispheric photographs. There was a strong species-dependent positive relationship between LMA and GSF for all species. Shade-tolerant species such as Fagus sylvatica showed lower LMA for the same GSF than less tolerant species as Quercus pyrenaica or Quercus petraea. The only evergreen species in the study, Ilex aquifollium, had the highest LMA, independent of light environment, with minimum values much higher than the rest of the broad-leaved species studied. There was no relation between N m and GSF for most species studied and only a very weak relation for the relative shade-intolerant species Q. pyrenaica. Within each species, the pattern of N a investment with regard to GSF was linked mainly to LMA. At the same relative irradiance, differences in N a among species were conditioned both by the LMA-GSF relationship and by the species N m value. The lowest N m value was measured in I. aquifollium (14.3 ± 0.6 mg g -1); intermediate values in Crataegus monogyna (16.9 ± 0.6 mg g -1) and Prunus avium (19.1 ± 0.6 mg g -1) and higher values, all in a narrow range (21.3 ± 0.6 to 23 ± 0.6 mg g -1), were measured for the other five species. Changes in LMA with the relative irradiance were linked both to lamina thickness (LT) and to palisade/spongy parenchyma ratio (PP/SP). In the second case, the LMA changes may be related to an increase in lamina density as palisade parenchyma involves higher cell packing than spongy parenchyma. However, since PP/SP ratio showed a weak species-specific relationship with LMA, the increase in LT should be the main cause of LMA variation.

  14. Sap flow is Underestimated by Thermal Dissipation Sensors due to Alterations of Wood Anatomy

    NASA Astrophysics Data System (ADS)

    Marañón-Jiménez, S.; Wiedemann, A.; van den Bulcke, J.; Cuntz, M.; Rebmann, C.; Steppe, K.

    2014-12-01

    The thermal dissipation technique (TD) is one of the most commonly adopted methods for sap flow measurements. However, underestimations of up to 60% of the tree transpiration have been reported with this technique, although the causes are not certainly known. The insertion of TD sensors within the stems causes damage of the wood tissue and subsequent healing reactions, changing wood anatomy and likely the sap flow path. However, the anatomical changes in response to the insertion of sap flow sensors and the effects on the measured flow have not been assessed yet. In this study, we investigate the alteration of vessel anatomy on wounds formed around TD sensors. Our main objectives were to elucidate the anatomical causes of sap flow underestimation for ring-porous and diffuse-porous species, and relate these changes to sap flow underestimations. Successive sets of TD probes were installed in early, mid and end of the growing season in Fagus sylvatica (diffuse-porous) and Quercus petraea (ring-porous) trees. They were logged after the growing season and additional sets of sensors were installed in the logged stems with presumably no healing reaction. The wood tissue surrounding each sensor was then excised and analysed by X-ray computed microtomography (X-ray micro CT). This technique allowed the quantification of vessel anatomical characteristics and the reconstruction of the 3-D internal microstructure of the xylem vessels so that extension and shape of the altered area could be determined. Gels and tyloses clogged the conductive vessels around the sensors in both beech and oak. The extension of the affected area was larger for beech although these anatomical changes led to similar sap flow underestimations in both species. The higher vessel size in oak may explain this result and, therefore, larger sap flow underestimation per area of affected conductive tissue. The wound healing reaction likely occurred within the first weeks after sensor installation, which

  15. An Empirical Study of the Wound Effects on Sap Flow Measured with Thermal Dissipation Probes

    NASA Astrophysics Data System (ADS)

    Wiedemann, A.; Marañón-Jiménez, S.; Herbst, M.; Cuntz, M.; Rebmann, C.

    2014-12-01

    Sap flow sensors are common to assess the contribution of tree transpiration to ecosystem evapotranspiration (ET). Thermal dissipation (TD) is one of the most popular methods for sap measurements but the insertion of TD probes in the tree stems imply wounding of the wood tissue and a consequent alteration of the sap flow. But the determination of sap flux density (SFD) is based on an empirical function developed for freshly drilled holes and it does hence not account for the wound effect. Here we investigate the effect of wound healing on sap flow measurements with TD probes. Our objectives were (1) the establishment of correction factors to account for the wound effect and (2) the determination of the point in time after installation when the correction factors become applicable. For that we performed an experiment in which TD probes were installed successively in diffuse- and ring-porous trees (Fagus sylvatica and Quercus petraea, resp.) during the growing season. The trees were logged in fall and additional sensors were installed afterwards in the logged stems. SFDs measured by the different TD sensors were compared with gravimetric estimates in the laboratory. Gravimetric flow compared well with SFD estimates from freshly installed sensors without wound formation, with only a slight underestimation by the TDs. In contrast, older sensors, submitted to wound reactions, underestimated SFD by up to 40%. However, sensors with 5, 11 and 22 week old wounds showed no significant differences, which implies that wound healing occurs in the first weeks after scission. Similar sap flow underestimations due to wound effects were observed in both species, oak and beech. This study highlights the relevance of accounting for tree wound reactions for accurate estimation of tree transpiration based on thermal dissipation sensors. We provide a correction factor for the classical Granier TD sensors that can be used from the first weeks after installation in similar species. This

  16. Pleistocene permafrost features in soils in the South-western Italian Alps

    NASA Astrophysics Data System (ADS)

    D'Amico, Michele; Catoni, Marcella; Bonifacio, Eleonora; Zanini, Ermanno

    2015-04-01

    Because of extensive Pleistocenic glaciations which erased most of the previously existing soils, slope steepness and climatic conditions favoring soil erosion, most soils observed on the Alps (and in other mid-latitude mountain ranges) developed only during the Holocene. However, in few sites, particularly in the outermost sections of the Alpine range, Pleistocene glaciers covered only small and scattered surfaces because of the low altitude reached in the basins, and ancient soils could be preserved for long periods of time on particularly stable surfaces. In some cases, these soils retain good memories of past periglacial activity. We described and sampled soils on stable surfaces in the Upper Tanaro valley, Ligurian Alps (Southwestern Piemonte, Italy). The sampling sites were between 600 to 1600 m of altitude, under present day lower montane Castanea sativa/Ostrya carpinifolia forests, montane Fagus sylvatica and Pinus uncinata forests or montane heath/grazed grassland, on different quartzitic substrata. The surface morphology often showed strongly developed, fossil periglacial patterned ground forms, such as coarse stone circles on flat surfaces, or stone stripes on steeper slopes. The stone circles could be up to 5 m wide, while the sorted stripes could be as wide as 12-15 m. A strong lateral cryogenic textural sorting characterized the fine fraction too, with sand dominating close to the stone rims of the patterned ground features and silt and clay the central parts. The surface 60-120 cm of the soils were podzolized during the Holocene; as a result of the textural lateral sorting, the thickness of the podzolic E and Bs horizons varied widely across the patterns. The lower boundary of the Holocene Podzols was abrupt, and corresponded with dense layers with thick coarse laminar structure and illuvial silt accumulation (Cjj horizons). Dense Cjj diapiric inclusions were sometimes preserved in the central parts of the patterns. Where cover beds were developed

  17. Does the precipitation redistribution of the canopy sense in the moisture pattern of the forest litter?

    NASA Astrophysics Data System (ADS)

    Zagyvai-Kiss, Katalin Anita; Kalicz, Péter; Csáfordi, Péter; Kucsara, Mihály; Gribovszki, Zoltán

    2013-04-01

    Precipitation is trapped and temporarily stored by the surfaces of forest crown (canopy interception) and forest litter (litter interception). The stemflow and throughfall reach the litter, thus theoretically the litter moisture content depends on these parts of precipitation. Nowadays the moisture pattern of the forest floor, both spatial and temporal scale, have growing respect for the forestry. The transition to the continuous cover forestry induce much higher variability compared to the even aged, more-less homogeneous, monocultural stands. The gap cutting is one of the key methods in the Hungarian forestry. There is an active discussion among the forest professionals how to determine the optimal gap size to maintain the optimal conditions for the seedlings. Among the open questions is how to modify surrounding trees the moisture pattern of the forest floor in the gap? In the early steps of a multidisciplinary project we processed some available data, to estimate the spatial dependency between the water content of forest litter and the spatial pattern of the canopy represented by the tree trunk. The maximum water content depends on dry weight of litter, thus we also analysed that parameter. Data were measured in three different forest ecosystems: a middle age beech (Fagus sylvatica), a sessile oak (Quercus petraea) and a spruce (Picea abies) stand. The study site (Hidegvíz Valley Research Cathcment) is located in Sopron Hills at the eastern border of the Alps. Litter samples were collected under each stand (occasionally 10-10 pieces from 40?40 cm area) and locations of the samples and neighbouring trees were mapped. We determined dry weight and the water content of litter in laboratory. The relationship between water content and the distance of tree trunks in case of spruce and oak stands were not significant and in case of the beech stand was weakly significant. Climate change effects can influence significantly forest floor moisture content, therefore this

  18. Soil organic matter dynamics under Beech and Hornbeam as affected by soil biological activity

    NASA Astrophysics Data System (ADS)

    Kooijman, A. M.; Cammeraat, L. H.

    2009-04-01

    Organic matter dynamics are highly affected both the soil fauna as well as the source of organic matter, having important consequences for the spatial heterogeneity of organic matter storage and conversion. We studied oldgrowth mixed deciduous forests in Central-Luxemburg on decalcified dolomitic marl, dominated by high-degradable hornbeam (Carpinus betulus L.) or low-degradable beech (Fagus sylvatica L.). Decomposition was measured both in the laboratory and in the field. Litter decomposition was higher for hornbeam than for beech under laboratory conditions, but especially in the field, which is mainly to be attributed to macro-fauna activity, specifically to earthworms (Lumbricus terrestris and Allolobophora species). We also investigated differences between beech and hornbeam with regard to litter input and habitat conditions. Total litter input was the same, but contribution of beech and hornbeam litter clearly differed between the two species. Also, mass of the ectorganic horizon and soil C:N ratio were significantly higher for beech, which was reflected in clear differences in the development of ectorganic profiles on top of the soil. Under beech a mull-moder was clearly present with a well developed fermentation and litter horizon, whereas under hornbeam all litter is incorporated into the soil, leaving the mineral soil surface bear in late summer (mull-type of horizon). In addition to litter quality, litter decomposition was affected by pH and soil moisture. Both pH and soil moisture were higher under hornbeam than under beech, which may reflect differences in soil development and litter quality effects over longer time scales. Under beech, dense layers of low-degradable litter may prevent erosion, and increase clay eluviation and leaching of base cations, leading to acid and dry conditions, which further decrease litter decay. Under hornbeam, the soil is not protected by a litter layer, and clay eluviation and acidification may be counteracted by erosion

  19. Rhizosphere effect on phosphorus availability in forest soils at different altitudes.

    NASA Astrophysics Data System (ADS)

    De Feudis, Mauro; Cardelli, Valeria; Massaccesi, Luisa; Bol, Roland; Willbold, Sabine; Cocco, Stefania; Corti, Giuseppe; Agnelli, Alberto

    2016-04-01

    Phosphorus (P) is an essential nutrient for plants but it is one of the least available mineral nutrients, and can substantially limit plant growth. Although plants are able to respond to the P shortage, the global warming might modify the soil-plant-microorganisms system and reduce P availability. We evaluated the rhizosphere effect of beech (Fagus sylvatica L.) in forest soils of the Apennines mountains (central Italy) at two altitudes (800 and 1000 m) and along 1° of latitudinal gradient, using latitude and altitude as proxies for temperature change. Specifically, we tested if 1) soil organic C, total N, and organic and available P decrease with increasing latitude and altitude, and 2) the rhizosphere effect on P availability becomes more pronounced when potential nutrient limitations are more severe, as it happens with increasing latitude and altitude. The results suggested that the small latitudinal gradient has no effect on soil properties. Conversely, significant changes occurred between 800 and 1000 m a.s.l., as the soils at higher altitude showed greater TOC, organic and available P contents, and alkaline mono-phosphatases activity than the soils at 800 m a.s.l. Compared to the soils at lower altitude, a marked rhizosphere effect was found at 1000 m a.s.l., and it was mainly attributed to the release of labile organics through rhizodeposition processes. These labile organic compounds were considered able to induce a "priming effect" that fostered the mineralization of the soil organic matter. The enhanced organic carbon cycling, in turn, likely promoted the mineralization of the organic P forms. This was supported by the smaller proportion of orthophosphate monoesters found in the P pool of the rhizosphere than in that of the soil far from the roots, with a consequent increase of the amount of available P. Hence, we speculate that at high altitude the energy supplied by the plants through rhizodeposition to the rhizosphere heterotrophic microbial

  20. Interactions between leaf nitrogen status and longevity in relation to N cycling in three contrasting European forest canopies

    NASA Astrophysics Data System (ADS)

    Wang, L.; Ibrom, A.; Korhonen, J. F. J.; Arnoud Frumau, K. F.; Wu, J.; Pihlatie, M.; Schjoerring, J. K.

    2012-07-01

    Seasonal and spatial variations in foliar nitrogen (N) parameters were investigated in three European forests with different tree species, viz. beech (Fagus sylvatica L.), Douglas fir (Pseudotsuga menziesii, Mirb., Franco) and Scots pine (Pinus sylvestris L.) in Denmark, The Netherlands and Finland, respectively. This was done in order to obtain information about functional acclimation, tree internal N conservation and its relevance for both ecosystem internal N cycling and foliar N exchange with the atmosphere. Leaf N pools generally showed much higher seasonal variability in beech trees than in the coniferous canopies. The concentrations of N and chlorophyll in the beech leaves were synchronized with the seasonal course of solar radiation implying close physiological acclimation, which was not observed in the coniferous needles. During phases of intensive N metabolism in the beech leaves, the NH4+ concentration rose considerably. This was compensated for by a strong pH decrease resulting in relatively low Γ values (ratio between tissue NH4+ and H+). The Γ values in the coniferous were even smaller than in beech, indicating low probability of NH3 emissions from the foliage to the atmosphere as an N conserving mechanism. The reduction in foliage N content during senescence was interpreted as N re-translocation from the senescing leaves into the rest of the trees. The N re-translocation efficiency (ηr) ranged from 37 to 70% and decreased with the time necessary for full renewal of the canopy foliage. Comparison with literature data from in total 23 tree species showed a general tendency for ηr to on average be reduced by 8% per year the canopy stays longer, i.e. with each additional year it takes for canopy renewal. The boreal pine site returned the lowest amount of N via foliage litter to the soil, while the temperate Douglas fir stand which had the largest peak canopy N content and the lowestηr returned the highest amount of N to the soil. These results

  1. Quantifying genetic variations and phenotypic plasticity of leaf phenology and growth for two temperate Fagaceae species (sessile oak and european beech)

    NASA Astrophysics Data System (ADS)

    Delzon, Sylvain; Vitasse, Yann; Alberto, Florian; Bresson, Caroline; Kremer, Antoine

    2010-05-01

    Under current climate change, research on inherent adaptive capacities of organisms is crucial to assess future evolutionary changes of natural populations. Genetic diversity and phenotypic plasticity constitute adaptative capacities that could allow populations to respond to new environmental conditions. The aim of the present study was (i) to determine whether there are genetic variations among populations from altitudinal gradients using a lowland common garden experiment and (ii) to assess the magnitude of phenotypic plasticity using a reciprocal transplant experiment (5 elevations from 100 to 1600 m asl.) for leaf phenology (flushing and senescence) and growth of two fagaceae species (Fagus sylvatica and Quercus petraea). We found significant differences in phenology among provenances for most species, and evidenced that these among-population differences in phenology were related to annual temperature of the provenance sites for both species. It's noteworthy that, along the same climatic gradient, the species exhibited opposite genetic clines: beech populations from high elevation flushed earlier than those of low elevation, whereas we observed an opposite trend for oak. Finally, we highlighted that both phenology timing and growth rate were highly consistent year to year. The results demonstrated that in spite of the proximity of the populations in their natural area, altitude led to genetic differentiations in their phenology and growth. Moreover, a high phenological plasticity was found for both species. We evidenced that reaction norms of flushing timing to temperature followed linear clinal trends for both species with an average shift of 5.7 days per degree increase. Timing of leaf senescence exhibited hyperbolic trends for beech and no or slight trends for oak. Furthermore, within species, there was no difference in magnitude of phenological plasticity among populations neither for flushing, nor for senescence. Consequently, for both species, the

  2. Does long-term cultivation of saplings under elevated CO2 concentration influence their photosynthetic response to temperature?

    PubMed Central

    Šigut, Ladislav; Holišová, Petra; Klem, Karel; Šprtová, Mirka; Calfapietra, Carlo; Marek, Michal V.; Špunda, Vladimír; Urban, Otmar

    2015-01-01

    Background and Aims Plants growing under elevated atmospheric CO2 concentrations often have reduced stomatal conductance and subsequently increased leaf temperature. This study therefore tested the hypothesis that under long-term elevated CO2 the temperature optima of photosynthetic processes will shift towards higher temperatures and the thermostability of the photosynthetic apparatus will increase. Methods The hypothesis was tested for saplings of broadleaved Fagus sylvatica and coniferous Picea abies exposed for 4–5 years to either ambient (AC; 385 µmol mol−1) or elevated (EC; 700 µmol mol−1) CO2 concentrations. Temperature response curves of photosynthetic processes were determined by gas-exchange and chlorophyll fluorescence techniques. Key Results Initial assumptions of reduced light-saturated stomatal conductance and increased leaf temperatures for EC plants were confirmed. Temperature response curves revealed stimulation of light-saturated rates of CO2 assimilation (Amax) and a decline in photorespiration (RL) as a result of EC within a wide temperature range. However, these effects were negligible or reduced at low and high temperatures. Higher temperature optima (Topt) of Amax, Rubisco carboxylation rates (VCmax) and RL were found for EC saplings compared with AC saplings. However, the shifts in Topt of Amax were instantaneous, and disappeared when measured at identical CO2 concentrations. Higher values of Topt at elevated CO2 were attributed particularly to reduced photorespiration and prevailing limitation of photosynthesis by ribulose-1,5-bisphosphate (RuBP) regeneration. Temperature response curves of fluorescence parameters suggested a negligible effect of EC on enhancement of thermostability of photosystem II photochemistry. Conclusions Elevated CO2 instantaneously increases temperature optima of Amax due to reduced photorespiration and limitation of photosynthesis by RuBP regeneration. However, this increase disappears when plants

  3. Novel, cyclic heat dissipation method for the correction of natural temperature gradients in sap flow measurements. Part 2. Laboratory validation.

    PubMed

    Reyes-Acosta, J Leonardo; Vandegehuchte, Maurits W; Steppe, Kathy; Lubczynski, Maciek W

    2012-07-01

    Sap flow measurements conducted with thermal dissipation probes (TDPs) are vulnerable to natural temperature gradient (NTG) bias. Few studies, however, attempted to explain the dynamics underlying the NTG formation and its influence on the sensors' signal. This study focused on understanding how the TDP signals are affected by negative and positive temperature influences from NTG and tested the novel cyclic heat dissipation (CHD) method to filter out the NTG bias. A series of three experiments were performed in which gravity-driven water flow was enforced on freshly cut stem segments of Fagus sylvatica L., while an artificial temperature gradient (ATG) was induced. The first experiment sought to confirm the incidence of the ATG on sensors. The second experiment established the mis-estimations caused by the biasing effect of the ATG on standard TDP measurements. The third experiment tested the accuracy of the CHD method to account for the ATG biasing effect, as compared with other cyclic correction methods. During experiments, sap flow measured by TDP was assessed against gravimetric measurements. The results show that negative and positive ATGs were comparable in pattern but substantially larger than field NTGs. Second, the ATG bias caused an overestimation of the standard TDP sap flux density of ∼17 cm(3) cm(-2) h(-1) by 76%, and the sap flux density of ∼2 cm(3) cm(-2) h(-1) by over 800%. Finally, the proposed CHD method successfully reduced the max. ATG bias to 25% at ∼11 cm(3) cm(-2) h(-1) and to 40% at ∼1 cm(3) cm(-2) h(-1). We concluded that: (i) the TDP method is susceptible to NTG especially at low flows; (ii) the CHD method successfully corrected the TDP signal and resulted in generally more accurate sap flux density estimates (mean absolute percentage error ranging between 11 and 21%) than standard constant power TDP method and other cyclic power methods; and (iii) the ATG enforcing system is a suitable way of re-creating NTG for future tests.

  4. Use of X-ray computed microtomography for non-invasive determination of wood anatomical characteristics.

    PubMed

    Steppe, Kathy; Cnudde, Veerle; Girard, Catherine; Lemeur, Raoul; Cnudde, Jean-Pierre; Jacobs, Patric

    2004-10-01

    Quantitative analysis of wood anatomical characteristics is usually performed using classical microtomy yielding optical micrographs of stained thin sections. It is time-consuming to obtain high quality cross-sections from microtomy, and sections can be damaged. This approach, therefore, is often impractical for those who need quick acquisition of quantitative data on vessel characteristics in wood. This paper reports results of a novel approach using X-ray computed microtomography (microCT) for non-invasive determination of wood anatomy. As a case study, stem wood samples of a 2-year-old beech (Fagus sylvatica L.) and a 3-year-old oak (Quercus robur L.) tree were investigated with this technique, beech being a diffuse-porous and oak a ring-porous tree species. MicroCT allowed non-invasive mapping of 2-D transverse cross-sections of both wood samples with micrometer resolution. Self-developed software 'microCTanalysis' was used for image processing of the 2-D cross-sections in order to automatically determine the inner vessel diameters, the transverse cross-sectional surface area of the vessels, the vessel density and the porosity with computer assistance. Performance of this new software was compared with manual analysis of the same micrographs. The automatically obtained results showed no significant statistical differences compared to the manual measurements. Visual inspection of the microCT slices revealed very good correspondence with the optical micrographs. Statistical analysis confirmed this observation in a more quantitative way, and it was, therefore, argued that anatomical analysis of optical micrographs can be readily substituted by automated use of microCT, and this without loss of accuracy. Furthermore, as an additional application of microCT, the 3-D renderings of the internal microstructure of the xylem vessels for both the beech and the oak sample could be reconstructed, clearly showing the complex nature of vessel networks. It can be concluded

  5. Intraspecific Variation in Wood Anatomical, Hydraulic, and Foliar Traits in Ten European Beech Provenances Differing in Growth Yield.

    PubMed

    Hajek, Peter; Kurjak, Daniel; von Wühlisch, Georg; Delzon, Sylvain; Schuldt, Bernhard

    2016-01-01

    In angiosperms, many studies have described the inter-specific variability of hydraulic-related traits and little is known at the intra-specific level. This information is however mandatory to assess the adaptive capacities of tree populations in the context of increasing drought frequency and severity. Ten 20-year old European beech (Fagus sylvatica L.) provenances representing the entire distribution range throughout Europe and differing significantly in aboveground biomass increment (ABI) by a factor of up to four were investigated for branch wood anatomical, hydraulic, and foliar traits in a provenance trial located in Northern Europe. We quantified to which extend xylem hydraulic and leaf traits are under genetic control and tested whether the xylem hydraulic properties (hydraulic efficiency and safety) trades off with yield and wood anatomical and leaf traits. Our results showed that only three out of 22 investigated ecophysiological traits showed significant genetic differentiations between provenances, namely vessel density (VD), the xylem pressure causing 88% loss of hydraulic conductance and mean leaf size. Depending of the ecophysiological traits measured, genetic differentiation between populations explained 0-14% of total phenotypic variation, while intra-population variability was higher than inter-population variability. Most wood anatomical traits and some foliar traits were additionally related to the climate of provenance origin. The lumen to sapwood area ratio, vessel diameter, theoretical specific conductivity and theoretical leaf-specific conductivity as well as the C:N-ratio increased with climatic aridity at the place of origin while the carbon isotope signature (δ(13)C) decreased. Contrary to our assumption, none of the wood anatomical traits were related to embolism resistance but were strong determinants of hydraulic efficiency. Although ABI was associated with both VD and δ(13)C, both hydraulic efficiency and embolism resistance were

  6. Wood structural differences between northern and southern beech provenances growing at a moderate site.

    PubMed

    Eilmann, B; Sterck, F; Wegner, L; de Vries, S M G; von Arx, G; Mohren, G M J; den Ouden, J; Sass-Klaassen, U

    2014-08-01

    Planting provenances originating from southern to northern locations has been discussed as a strategy to speed up species migration and mitigate negative effects of climate change on forest stability and productivity. Especially for drought-susceptible species such as European beech (Fagus sylvatica L.), the introduction of drought-tolerant provenances from the south could be an option. Yet, beech has been found to respond plastically to environmental conditions, suggesting that the climate on the plantation site might be more important for tree growth than the genetic predisposition of potentially drought-adapted provenances. In this study, we compared the radial growth, wood-anatomical traits and leaf phenology of four beech provenances originating from southern (Bulgaria, France) and northern locations (Sweden, the Netherlands) and planted in a provenance trial in the Netherlands. The distribution of precipitation largely differs between the sites of origin. The northern provenances experience a maximum and the southern provenances experience a minimum of rainfall in summer. We compared tree productivity and the anatomy of the water-conducting system for the period from 2000 to 2010, including the drought year 2003. In addition, tree mortality and the timing of leaf unfolding in spring were analysed for the years 2001, 2007 and 2012. Comparison of these traits in the four beech provenances indicates the influence of genetic predisposition and local environmental factors on the performance of these provenances under moderate site conditions. Variation in radial growth was controlled by environment, although the growth level slightly differed due to genetic background. The Bulgarian provenance had an efficient water-conducting system which was moreover unaffected by the drought in 2003, pointing to a high ability of this provenance to cope well with dry conditions. In addition, the Bulgarian provenance showed up as most productive in terms of height and radial

  7. Impacts of climate and land-use changes on mountain forests in Central Apennines

    NASA Astrophysics Data System (ADS)

    Calderaro, Chiara; Palombo, Caterina; Tognetti, Roberto; Marchetti, Marco

    2016-04-01

    The present study aims to analyze the vegetation dynamics of Pinus mugo Turra subsp. mugo and Fagus sylvatica (L.) at the treeline ecotone between the closed beech forest and the mountain pine krummholz vegetation. This transitional ecosystem zone dominates the high altitudes of the Majella massif, (Central Appennines) and represents the exception on the Apennines chain being treeline dominated by krummholz with mountain pine. This species in the Majella National Park is re-colonizing open areas both upward, to the alpine meadows, and downward, to areas potentially suitable by beech expansion. On the Apennine chain, Central Italy, global change could cause a negative impact on the spatial distribution of rare or endemic species, thus influencing the appearance, structure and productivity of the tree-line ecotone. Mountain pine, growing over the treeline, represents a very sensitive species to the effects of climate change acting in Mediterranean basin. In four sampling site a circular area of 40 m in diameter was established between beech forest and mountain pine krhummolz. For both species, dendrometric parameters were collected and woody cores were extracted. During sampling, basic information, to define the growth dynamics and competition between the two species, were also recorded. A landscape analysis from aerial photographs provided information to better understand the development dynamics of the two plant communities. The dendrochronological analysis, supported by dendrometric parameters, defined the population age, as well as the time of settlement. Climate-growth relationships was analized and showed responses, in terms of plant growth, to the current climate trend. The influence of temperature and precipitation on tree growth during the vegetation season was demonstrated by significant correlation coefficients, particularly for spring and summer temperatures and summer precipitation, in both species. An interesting result is the negative correlation of

  8. The dynamic of the annual carbon allocation to wood in European tree species is consistent with a combined source-sink limitation of growth: implications for modelling

    NASA Astrophysics Data System (ADS)

    Guillemot, J.; Martin-StPaul, N. K.; Dufrene, E.; Francois, C.; Soudani, K.; Ourcival, J. M.; Delpierre, N.

    2015-05-01

    The extent to which wood growth is limited by carbon (C) supply (i.e. source control) or by cambial activity (i.e. sink control) will strongly determine the responses of trees to global changes. Nevertheless, the physiological processes that are responsible for limiting forest growth are still a matter of debate. The aim of this study was to evaluate the key determinants of the annual C allocation to wood along large soil and climate regional gradients over France. The study was conducted for five tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex, Quercus robur and Picea abies). The drivers of stand biomass growth were assessed on both inter-site and inter-annual scales. Our data set comprised field measurements performed at 49 sites (931 site-years) that included biometric measurements and a variety of stand characteristics (e.g. soil water holding capacity, leaf area index). It was complemented with process-based simulations when possible explanatory variables could not be directly measured (e.g. annual and seasonal tree C balance, bioclimatic water stress indices). Specifically, the relative influences of tree C balance (source control), direct environmental control (water and temperature controls of sink activity) and allocation adjustments related to age, past climate conditions, competition intensity and soil nutrient availability on growth were quantified. The inter-site variability in the stand C allocation to wood was predominantly driven by age-related decline. The direct effects of temperature and water stress on sink activity (i.e. effects independent from their effects on the C supply) exerted a strong influence on the annual stand wood growth in all of the species considered, including deciduous temperate species. The lagged effect of the past environmental conditions (e.g. the previous year's water stress and low C uptake) significantly affected the annual C allocation to wood. The C supply

  9. The dynamics of annual carbon allocation to wood in European forests is consistent with a combined source-sink limitation of growth.

    NASA Astrophysics Data System (ADS)

    Guillemot, Joannès; Martin-StPaul, Nicolas K.; Dufrêne, Eric; François, Christophe; Soudani, Kamel; Ourcival, Jean-Marc; Leadley, Paul; Delpierre, Nicolas

    2015-04-01

    The extent to which forest growth is limited by carbon (C) supply (source control) or by cambial activity (sink control) will strongly determines the responses of trees to global changes. However, the physiological processes responsible for the limitation of forest growth are still under debate. The aim of this study was i) to evaluate the key drivers of the annual carbon allocation to wood along large soil and climate regional gradients in four tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex and Picea abies) ii) to implement the identified key drivers in a new C allocation scheme within the CASTANEA terrestrial biosphere model (TBM). Combining field measurements and process-based simulations at 49 sites (931 site-years), our analyses revealed that the inter-site variability in C allocation to wood was predominantly driven by an age-related decline. The direct control of temperature or water stress on sink activity (i.e. independently from their effects on C supply) exerted a strong influence on the annual woody growth in all the species considered, including deciduous temperate species. The lagged effect of the past environment conditions was a significant driver of the annual C allocation to wood. Carbon supply appeared to strongly limit growth only in deciduous temperate species. Our study supports the premise that European forest growth is under a complex panel of source- and sink- limitations, contradicting the simple source control implemented in most TBMs. The implementation of these combined forest growth limitations in the CASTANEA model significantly improved its performance when evaluated against independent stand growth data at the regional scale (mainland France, >10000 plots). We finally discuss how the sink imitation affects the CASTANEA simulated projections of forest productivity along the 21th century, especially with respect to the expected fertilizing effect of increasing atmospheric

  10. The Dynamic of Annual Carbon Allocation to Wood in European Forests Is Consistent with a Combined Source-Sink Limitation of Growth: Implications on Growth Simulations in a Terrestrial Biosphere Model

    NASA Astrophysics Data System (ADS)

    Guillemot, J.; Martin-StPaul, N. K.; Dufrêne, E.; François, C.; Soudani, K.; Ourcival, J. M.; Leadley, P.; Delpierre, N.

    2014-12-01

    The extent to which forest growth is limited by carbon (C) supply (source control) or by cambial activity (sink control) will strongly determines the responses of trees to global changes. However, the physiological processes responsible for the limitation of forest growth are still under debate. The aim of this study was i) to evaluate the key drivers of the annual carbon allocation to wood along large soil and climate regional gradients in four tree species representative of the main European forest biomes (Fagus sylvatica, Quercus petraea, Quercus ilex and Picea abies) ii) to implement the identified key drivers in a new C allocation scheme within the CASTANEA terrestrial biosphere model (TBM). Combining field measurements and process-based simulations at 49 sites (931 site-years), our analyses revealed that the inter-site variability in C allocation to wood was predominantly driven by an age-related decline. The direct control of temperature or water stress on sink activity (i.e. independently from their effects on C supply) exerted a strong influence on the annual woody growth in all the species considered, including deciduous temperate species. The lagged effect of the past environment conditions was a significant driver of the annual C allocation to wood. Carbon supply appeared to strongly limit growth only in deciduous temperate species. Our study supports the premise that European forest growth is under a complex panel of source- and sink- limitations, contradicting the simple source control implemented in most TBMs. The implementation of these combined forest growth limitations in the CASTANEA model significantly improved its performance when evaluated against independent stand growth data at the regional scale (mainland France, >103 plots). We finally discuss how the sink imitation affects the CASTANEA simulated projections of forest productivity along the 21th century, especially with respect to the expected fertilizing effect of increasing atmospheric

  11. Metatranscriptomics reveals the diversity of genes expressed by eukaryotes in forest soils.

    PubMed

    Damon, Coralie; Lehembre, Frédéric; Oger-Desfeux, Christine; Luis, Patricia; Ranger, Jacques; Fraissinet-Tachet, Laurence; Marmeisse, Roland

    2012-01-01

    Eukaryotic organisms play essential roles in the biology and fertility of soils. For example the micro and mesofauna contribute to the fragmentation and homogenization of plant organic matter, while its hydrolysis is primarily performed by the fungi. To get a global picture of the activities carried out by soil eukaryotes we sequenced 2×10,000 cDNAs synthesized from polyadenylated mRNA directly extracted from soils sampled in beech (Fagus sylvatica) and spruce (Picea abies) forests. Taxonomic affiliation of both cDNAs and 18S rRNA sequences showed a dominance of sequences from fungi (up to 60%) and metazoans while protists represented less than 12% of the 18S rRNA sequences. Sixty percent of cDNA sequences from beech forest soil and 52% from spruce forest soil had no homologs in the GenBank/EMBL/DDJB protein database. A Gene Ontology term was attributed to 39% and 31.5% of the spruce and beech soil sequences respectively. Altogether 2076 sequences were putative homologs to different enzyme classes participating to 129 KEGG pathways among which several were implicated in the utilisation of soil nutrients such as nitrogen (ammonium, amino acids, oligopeptides), sugars, phosphates and sulfate. Specific annotation of plant cell wall degrading enzymes identified enzymes active on major polymers (cellulose, hemicelluloses, pectin, lignin) and glycoside hydrolases represented 0.5% (beech soil)-0.8% (spruce soil) of the cDNAs. Other sequences coding enzymes active on organic matter (extracellular proteases, lipases, a phytase, P450 monooxygenases) were identified, thus underlining the biotechnological potential of eukaryotic metatranscriptomes. The phylogenetic affiliation of 12 full-length carbohydrate active enzymes showed that most of them were distantly related to sequences from known fungi. For example, a putative GH45 endocellulase was closely associated to molluscan sequences, while a GH7 cellobiohydrolase was closest to crustacean sequences, thus suggesting a

  12. Tree species effects on decomposition and forest floor dynamics in a common garden.

    PubMed

    Hobbie, Sarah E; Reich, Peter B; Oleksyn, Jacek; Ogdahl, Megan; Zytkowiak, Roma; Hale, Cynthia; Karolewski, Piotr

    2006-09-01

    We studied the effects of tree species on leaf litter decomposition and forest floor dynamics in a common garden experiment of 14 tree species (Abies alba, Acer platanoides, Acer pseudoplatanus, Betula pendula, Carpinus betulus, Fagus sylvatica, Larix decidua, Picea abies, Pinus nigra, Pinus sylvestris, Pseudotsuga menziesii, Quercus robur, Quercus rubra, and Tilia cordata) in southwestern Poland. We used three simultaneous litter bag experiments to tease apart species effects on decomposition via leaf litter chemistry vs. effects on the decomposition environment. Decomposition rates of litter in its plot of origin were negatively correlated with litter lignin and positively correlated with mean annual soil temperature (MAT(soil)) across species. Likewise, decomposition of a common litter type across all plots was positively associated with MAT(soil), and decomposition of litter from all plots in a common plot was negatively related to litter lignin but positively related to litter Ca. Taken together, these results indicate that tree species influenced microbial decomposition primarily via differences in litter lignin (and secondarily, via differences in litter Ca), with high-lignin (and low-Ca) species decomposing most slowly, and by affecting MAT(soil), with warmer plots exhibiting more rapid decomposition. In addition to litter bag experiments, we examined forest floor dynamics in each plot by mass balance, since earthworms were a known component of these forest stands and their access to litter in litter bags was limited. Forest floor removal rates estimated from mass balance were positively related to leaf litter Ca (and unrelated to decay rates obtained using litter bags). Litter Ca, in turn, was positively related to the abundance of earthworms, particularly Lumbricus terrestris. Thus, while species influence microbially mediated decomposition primarily through differences in litter lignin, differences among species in litter Ca are most important in

  13. 7 CFR 301.92-2 - Restricted, regulated, and associated articles; lists of proven hosts and associated plant taxa.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... chestnut *Arbutus menziesii Madrone *Arctostaphylos manzanita Manzanita *Calluna vulgaris Scotch heather *Camellia spp. Camellia—all species, hybrids and cultivars *Castanea sativa Sweet chestnut Fagus...

  14. 7 CFR 301.92-2 - Restricted, regulated, and associated articles; lists of proven hosts and associated plant taxa.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... chestnut *Arbutus menziesii Madrone *Arctostaphylos manzanita Manzanita *Calluna vulgaris Scotch heather *Camellia spp. Camellia—all species, hybrids and cultivars *Castanea sativa Sweet chestnut Fagus...

  15. 7 CFR 301.92-2 - Restricted, regulated, and associated articles; lists of proven hosts and associated plant taxa.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... chestnut *Arbutus menziesii Madrone *Arctostaphylos manzanita Manzanita *Calluna vulgaris Scotch heather *Camellia spp. Camellia—all species, hybrids and cultivars *Castanea sativa Sweet chestnut Fagus...

  16. 7 CFR 301.92-2 - Restricted, regulated, and associated articles; lists of proven hosts and associated plant taxa.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... chestnut *Arbutus menziesii Madrone *Arctostaphylos manzanita Manzanita *Calluna vulgaris Scotch heather *Camellia spp. Camellia—all species, hybrids and cultivars *Castanea sativa Sweet chestnut Fagus...

  17. 7 CFR 301.92-2 - Restricted, regulated, and associated articles; lists of proven hosts and associated plant taxa.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... chestnut *Arbutus menziesii Madrone *Arctostaphylos manzanita Manzanita *Calluna vulgaris Scotch heather *Camellia spp. Camellia—all species, hybrids and cultivars *Castanea sativa Sweet chestnut Fagus...

  18. Chlorophyll fluorescence kinetics, photosynthetic activity, and pigment composition of blue-shade and half-shade leaves as compared to sun and shade leaves of different trees.

    PubMed

    Lichtenthaler, Hartmut K; Babani, Fatbardha; Navrátil, Martin; Buschmann, Claus

    2013-11-01

    The chlorophyll (Chl) fluorescence induction kinetics, net photosynthetic CO2 fixation rates P N, and composition of photosynthetic pigments of differently light exposed leaves of several trees were comparatively measured to determine the differences in photosynthetic activity and pigment adaptation of leaves. The functional measurements were carried out with sun, half-shade and shade leaves of seven different trees species. These were: Acer platanoides L., Ginkgo biloba L., Fagus sylvatica L., Platanus x acerifolia Willd., Populus nigra L., Quercus robur L., Tilia cordata Mill. In three cases (beech, ginkgo, and oak), we compared the Chl fluorescence kinetics and photosynthetic rates of blue-shade leaves of the north tree crown receiving only blue sky light but no direct sunlight with that of sun leaves. In these cases, we also determined in detail the pigment composition of all four leaf types. In addition, we determined the quantum irradiance and spectral irradiance of direct sunlight, blue skylight as well as the irradiance in half shade and full shade. The results indicate that sun leaves possess significantly higher mean values for the net CO2 fixation rates P N (7.8-10.7 μmol CO2 m(-2) s(-1) leaf area) and the Chl fluorescence ratio R Fd (3.85-4.46) as compared to shade leaves (mean P N of 2.6-3.8 μmol CO2 m(-2) s(-1) leaf area.; mean R Fd of 1.94-2.56). Sun leaves also exhibit higher mean values for the pigment ratio Chl a/b (3.14-3.31) and considerably lower values for the weight ratio total chlorophylls to total carotenoids, (a + b)/(x + c), (4.07-4.25) as compared to shade leaves (Chl a/b 2.62-2.72) and (a + b)/(x + c) of 5.18-5.54. Blue-shade and half-shade leaves have an intermediate position between sun and shade leaves in all investigated parameters including the ratio F v/F o (maximum quantum yield of PS2 photochemistry) and are significantly different from sun and shade leaves but could not be differentiated from each other. The

  19. Carbohydrates and thermal analysis reflects changes in soil organic matter stability after forest expansion on abandoned grassland

    NASA Astrophysics Data System (ADS)

    Guidi, Claudia; Vesterdal, Lars; Cannella, David; Leifeld, Jens; Gianelle, Damiano; Rodeghiero, Mirco

    2014-05-01

    Grassland abandonment, followed by progressive forest expansion, is the dominant land-use change in the Southern Alps, Europe. Land-use change can affect not only the amount of organic matter (OM) in soil but also its composition and stability. Our objective was to investigate changes in organic matter properties after forest expansion on abandoned grasslands, combining analysis of carbohydrates, indicative of labile OM compounds with prevalent plant or microbial origin, with thermal analysis. Thermal analysis was used as a rapid assessment method for the characterization of SOM stability. A land-use gradient was investigated in four land-use types in the subalpine area of Trentino region, Italy: i) managed grassland, mown and fertilized for the past 100 years; ii) grassland abandoned since 10 years, with sparse shrubs and Picea abies saplings; iii) early-stage forest, dominated by P. abies and established on a grassland abandoned around 1970; iv) old forest, dominated by Fagus sylvatica and P. abies. Mineral soil was sampled at three subplots in each land use type with eight soil cores, which were subsequently pooled by depth (0-5 cm, 5-10 cm, 10-20 cm). Sugars were extracted from bulk soil samples through acid hydrolysis with H2SO4 (0.5 M). The analytical composition of sugar monomers was performed with HPAEC technology (Dionex ICS5000), equipped with PAD-detection. Thermal stability was assessed with a differential scanning calorimeter DSC100, heating soil samples up to 600°C at a heating rate of 10°C min-1 in synthetic air. Peak height (W g OC-1) of 1st DSC exotherm, dominated by burning of labile OM compounds, was used as thermal stability index. In the abandoned grassland, carbohydrates compounds accounted for a greater proportion of soil OC than in other land use types. Microbially derived sugars, as rhamnose and galactose, were more abundant in managed and abandoned grasslands compared with early-stage and old forest. The amount of thermally labile sugars

  20. Determining the sensitivity of the high mountain region in Northern Romania to climate and land use changes through multi-proxy analysis

    NASA Astrophysics Data System (ADS)

    Feurdean, Angelica; Geanta, Anca; Tantau, Ioan; Auer, Andreea; Hutchinson, Simon

    2013-04-01

    Climate and land use changes can have a great impact on high altitude environments due to their species' narrow tolerance capabilities, habitat fragmentation and habitat restriction. Since trees at the timberline and the treeline ecotone grow at their temperature and soil tolerance limit, even small alterations in these parameters can result in marked changes in the position of the treeline ecotone, diversity, and species composition. Current and future climate warming is anticipated to shift the tree and timberlines upwards, whereas land use changes can drive this movement in the opposite direction. Therefore the long-term responses of vegetation to past climate variations and land use changes are of particular relevance for the prediction of future vegetation change in high mountain areas. Here, we use a multi-proxy analysis (pollen, spores, micro and macrocharcoal, mineral magnetic properties and AMS 14C dating) of a 1m lacustrine sequence covering the last 5000 years located in the subalpine zone (1910 m a.s.l.) in the Rodna Mountains (Northern Romanian Carpathians) to determine the sensitivity of high mountain habitats (i.e., movements of the timberline and treeline ecotones, and changes in vegetation composition diversity) in response to climate, fires and land use. The pollen and stomata records reveal regional forests dominated by Pinus sylvestris between ca. 5000 and 4250 cal yrs BP, which were replaced by Picea abies, Abies alba and Fagus sylvatica from about 4200 cal yrs BP onwards. The proximity of the lake was treeless, dominated by sub-alpine shrubs (Alnus viridis), alpine herbaceous communities (Poaceae, Cyperaceae, Apiaceae, Asteraceae Tubuliflorae, A. Liguliflorae, Thalictrum) and ruderal species (Artemisia, Rumex, Chenopodiaceae) through almost the whole record. However, Pinus stomata found between 5000 and 4000 cal yr BP probably indicate a higher position of the treeline and the local occurrence of Pinus before 4000 cal yr BP. Our results show

  1. Photosynthetic activity, chloroplast ultrastructure, and leaf characteristics of high-light and low-light plants and of sun and shade leaves.

    PubMed

    Lichtenthaler, H K; Buschmann, C; Döll, M; Fietz, H J; Bach, T; Kozel, U; Meier, D; Rahmsdorf, U

    1981-06-01

    The photosynthetic CO2-fixation rates, chlorophyll content, chloroplast ultrastructure and other leaf characteristics (e.g. variable fluorescence, stomata density, soluble carbohydrate content) were studied in a comparative way in sun and shade leaves of beech (Fagus sylvatica) and in high-light and low-light seedlings. 1. Sun leaves of the beech possess a smaller leaf area, higher dry weight, lower water content, higher stomata density, higher chlorophyll a/b ratios and are thicker than the shade leaves. Sun leaves on the average contain more chlorophyll in a leaf area unit; the shade leaf exhibits more chlorophyll on a dry weight basis. Sun leaves show higher rates for dark respiration and a higher light saturation of photosynthetic CO2-fixation. Above 2000 lux they are more efficient in photosynthetic quantum conversion than the shade leaves. 2. The development of HL-radish plants proceeds much faster than that of LL-plants. The cotyledons of HL-plants show a higher dry weight, lower water content, a higher ratio of chlorophyll a/b and a higher gross photosynthesis rate than the cotyledons of the LL-plants, which possess a higher chlorophyll content per dry weight basis. The large area of the HL-cotyledon on the one hand, as well as the higher stomata density and the higher respiration rate in the LL-cotyledon on the other hand, are not in agreement with the characteristics of sun and shade leaves respectively. 3. The development, growth and wilting of wheat leaves and the appearance of the following leaves (leaf succession) is much faster at high quanta fluence rates than in weak light. The chlorophyll content is higher in the HL-leaf per unit leaf area and in the LL-leaf per g dry weight. There are no differences in the stomata density and leaf area between the HL- and LL-leaf. There are fewer differences between HL- and LL-leaves than in beech or radish leaves. 4. The chloroplast ultrastructure of shade-type chloroplasts (shade leaves, LL-leaves) is not only

  2. The importance of catchment vegetation for lake sediment mercury records

    NASA Astrophysics Data System (ADS)

    Rydberg, Johan; Rösch, Manfred; Heinz, Emanuel; Biester, Harald

    2014-05-01

    In this study we have used a long, Holocene, sediment profile from a small headwater lake in Southern Germany to determine how changes in the vegetation affected the sediment accumulation in general and the accumulation of mercury in particular. The sediment samples were analyzed for their content of total mercury, organic matter quality/quantity and geochemical composition, and the vegetation development was determined using pollen analysis. Over the course of the Holocene, two major shifts in vegetation occurred, both coincide with changes in mercury accumulation. The period prior to 9000 BP was dominated by non-forest vegetation (e.g., Corylus avellana), and mercury concentrations around 60 ng g-1 (90 μg m-2 yr-1). About 8500 BP there was a shift to forest vegetation (mainly Quercus robur), which coincides with increases in both mercury concentrations and accumulation rates (115 ng g-1 and 140 μg m-2 yr-1, respectively). This vegetation shift also drastically decreased the influx of mineral particles to the lake, likely because the development of a closed forest decreased soil erosion. During the following 3500 years - when the vegetation remained dominated by Quercus robur - mercury concentrations were stable around 115 ng g-1, while mercury accumulation rates decreased to about 110 μg m-2 yr-1 due to a gradual decrease in sediment accumulation during the latter part of this period. Around 5000 BP there is a second shift in the vegetation as Quercus robur is replaced by Fagus sylvatica and Abies alba as the dominant tree species, and again this shift leads to an increase in both mercury concentrations and mercury accumulation rates (200 ng g-1 and 140 μg m-2 yr-1, respectively). This shows that the vegetation - and not only the concentration of mercury in the atmosphere - has an influence on the amount of mercury that is accumulated in a lake's sediment. Firstly, the vegetation will influence the interception of mercury, and other atmospherically derived

  3. Soil humus composition - comparison between mountain grasslands and forest lands with different land-use intensity

    NASA Astrophysics Data System (ADS)

    Naydenova, Lora; Zhiyanski, Miglena; Leifeld, Jens; Filcheva, Ekaterina

    2015-04-01

    Soil humus is a dynamic characteristic greatly vulnerable to land use and climate and with important feedbacks to the atmospheric green house gas balance and the rate of climate change. The increased demand for accurate soil carbon stocks assessments and predictions of its changes as a result of land use/cover and climate change has triggered large-scale and long-term measurements of soil organic matter specifics. We studied the soil humus composition in four mountain grasslands, differentiated according to the land-use sub-type and land-use intensity and four forest lands. Two pastures - with intensive (Pi) and extensive grazing (Pe) and two meadows- managed (Mm) and unmanaged (Mu) were objects of present study. Two spruce plantations (Picea abies Karst), and two natural beech forests (Fagus sylvatica L.) - control, unmanaged for the both (Su and Bu) and with 10 % cutting intensity (Sc and Bc). Humus composition was analyzed following the methodology of Kononova-Belchikova. The aggressive and mobile fulvic acids predominated in all of the investigated plots, except Pe and Bu. Humic acids are "free" and bonded with R3O3 and no Ca-bonded humic acids were established under the grasslands, but in the soils under the two beech forest we observed Ca-bonded humic acids in small quantities. The values of total org. C and C-extracted by 0.1 N NaOH was similar in most of studied horizons. Our results showed that the highest total carbon content was localized in the organic-mineral soil horizon and decreased toward deeper soil. The highest total carbon content estimated at 14.04 % was determined in A-horizon of soil in pasture with extensive grazing, for the grasslands. The higher grazing disturbance in Pi leads to increase root biomass in patch areas and in inter-patch upper soil related with decrease of soil humus content. We supposed that the reduced amount of litter input with increased recalcitrance to decomposition provoked the reduction of organic carbon content and

  4. Finders keepers, losers weepers - drought as a modifier of competition between European beech and Norway spruce -

    NASA Astrophysics Data System (ADS)

    Goisser, Michael; Blanck, Christian; Geppert, Uwe; Häberle, Karl-Heinz; Matyssek, Rainer; Grams, Thorsten E. E.

    2016-04-01

    Mixed stands of European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst.) frequently reflect over-yielding, when compared to respective monospecific stands. Over-yielding is attributed to enhanced resource uptake efficiency through niche complementarity alleviating species competition. Under climate change, however, with severe and frequent summer drought, water limitation may become crucial in modifying the competitive interaction between neighboring beech and spruce trees. In view of the demands by silvicultural practice, basic knowledge from experimental field work about competitive versus facilitative interaction in maturing mixed beech-spruce forests is scarce. To this end, we investigate species-specific drought response including underlying mechanisms of species interaction in a maturing group-wise mixed beech-spruce forest, amongst 60 and 53 adult trees of beech and spruce, respectively (spruce 65 ± 2, beech 85 ± 4 years old). Severe and repeated experimental drought is being induced over several years through a stand-scale approach of rain throughfall exclusion (Kranzberg Forest Roof Experiment, KROOF). The experimental design comprises 6 roofed (E, automated, closing only during rain) and 6 control (C) plots with a total area of almost 1800 square meters. In 2015 minimum predawn potentials of -2.16 MPa and -2.26 MPa were reached in E for beech and spruce respectively. At the leaf level, spruce displayed high drought susceptibility reflected by a distinct decrease in both stomatal conductance and net CO2 uptake rate by more than 80% each, suggesting isohydric response. Beech rather displayed anisohydry indicated by less pronounced yet significant reduction of stomatal conductance and net CO2 uptake rate by more than 55% and 45%, respectively. Under the C regime, a negative species interaction effect on stomatal conductance was found in beech, contrasting with a positive effect in spruce. However, drought reversed the effect of

  5. Effect of temperate climate tree species on gross ammonification, gross nitrification and N2O formation

    NASA Astrophysics Data System (ADS)

    Brüggemann, N.; Rosenkranz, P.; Papen, H.; Butterbach-Bahl, K.

    2003-04-01

    Microbial nitrogen turnover processes in the soil, like ammonification, nitrification and denitrification, play an important role in the formation of nitrous oxide (N2O): (i) ammonification, because it releases nitrogen from organic material in the form of ammonium (NH4+), which in turn can serve as substrate for nitrification; (ii) nitrification itself (i.e. the turnover of NH4+ to nitrate, NO3-), during which nitric oxide (NO) and N2O can be released as by-products at varying ratios; (iii) denitrification, in which NO3- serves as electron acceptor and is converted to molecular nitrogen (N2) via NO and N2O as intermediates, that can also be partially lost to the atmosphere. Temperate forest soils are a substantial source of atmospheric N2O contributing up to 10% to the total atmospheric N2O budget. However, this figure is afflicted with a huge uncertainty due to a number of factors governing the soil N2O formation, consumption, release and uptake, which are not fully understood at present. To one of these factors belongs the influence of the tree species on nitrogen turnover processes in the soil and the formation of N trace gases related with them. The aim of the present work was to analyse this tree species effect for the temperate climate region. For this purpose the effect of five different temperate tree species, having the same age and growing on the same soil in direct vicinity to each other, on gross ammonification and gross nitrification as well as on N2O formation was investigated. The trees (common beech, Fagus sylvatica; pedunculate oak, Quercus robur; Norway spruce, Picea abies; Japanese larch, Larix leptolepis; mountain pine, Pinus mugo) were part of a species trial in Western Jutland, Denmark, established in 1965 on a former sandy heathland. Samples from the soil under these five tree species were taken in spring and in summer 2002, respectively, differentiating between organic layer and mineral soil. The gross rates of ammonification as well of

  6. MODIS Vegetation Indices time series improvement considering real acquisition dates

    NASA Astrophysics Data System (ADS)

    Testa, S.; Borgogno Mondino, E.

    2013-12-01

    Satellite Vegetation Indices (VI) time series images are widely used for the characterization phenology, which requires a high temporal accuracy of the satellite data. The present work is based on the MODerate resolution Imaging Spectroradiometer (MODIS) MOD13Q1 product - Vegetation Indices 16-Day L3 Global 250m, which is generated through a maximum value compositing process that reduces the number of cloudy pixels and excludes, when possible, off-nadir ones. Because of its 16-days compositing period, the distance between two adjacent-in-time values within each pixel NDVI time series can range from 1 to 32 days, thus not acceptable for phenologic studies. Moreover, most of the available smoothing algorithms, which are widely used for phenology characterization, assume that data points are equidistant in time and contemporary over the image. The objective of this work was to assess temporal features of NDVI time series over a test area, composed by Castanea sativa (chestnut) and Fagus sylvatica (beech) pure pixels within the Piemonte region in Northwestern Italy. Firstly, NDVI, Pixel Reliability (PR) and Composite Day of the Year (CDOY) data ranging from 2000 to 2011 were extracted from MOD13Q1 and corresponding time series were generated (in further computations, 2000 was not considered since it is not complete because acquisition began in February and calibration is unreliable until October). Analysis of CDOY time series (containing the actual reference date of each NDVI value) over the selected study areas showed NDVI values to be prevalently generated from data acquired at the centre of each 16-days period (the 9th day), at least constantly along the year. This leads to consider each original NDVI value nominally placed to the centre of its 16-days reference period. Then, a new NDVI time series was generated: a) moving each NDVI value to its actual "acquisition" date, b) interpolating the obtained temporary time series through SPLINE functions, c) sampling such

  7. Explaining the variability of Photochemical Reflectance Index (PRI): deconvolution of variability related to Light Use Efficiency and Canopy attributes.

    NASA Astrophysics Data System (ADS)

    Merlier, Elodie; Hmimina, Gabriel; Dufrêne, Eric; Soudani, Kamel

    2014-05-01

    The Photochemical Reflectance Index (PRI) was designed as a proxy of the state of xanthophyll cycle which is used as a response of plants to excess of light (Gamon et al., 1990; 1992). Strong relationships between PRI and LUE were shown at leaf and canopy scales and over a wide range of species (Garbulsky et al., 2011). However, its use at canopy scale was shown to be significantly hampered by effects of confounding factors such as the PRI sensitivity to leaf pigment content (Gamon et al. 2001; Nakaji et al. 2006) and to canopy structure (Hilker et al. 2008). Several approaches aimed at correcting such effects and recent works focused on the deconvolution of LUE related and LUE unrelated PRI variability (Rahimzadeh-Bajgiran et al. 2012).In this study, the PRI variability at canopy scale is investigated over two years on three species (Fagus sylvatica, Quercus robur and Pinus sylvestris) growing under two water regimes. At daily scale, PRI variability is mainly explained by radiation conditions. As already reported at leaf scale in Hmimina et al. (2014), analysis of PRI responses to incoming photosynthetically active radiation over seasonal scale allowed to separate two sources of variability : a constitutive variability mainly related to canopy structure and leaf chlorophyll content and a facultative variability mainly related to LUE and soil moisture content. These results highlight the composite nature of PRI signal measured at canopy scale and the importance of disentangling its sources of variability in order to accurately assess ecosystem light use efficiency. Gamon JA, Field CB, Bilger W, Björkman O, Fredeen AL, Peñuelas J. 1990. Remote sensing of the xanthophyll cycle and chlorophyll fluorescence in sunflower leaves and canopies. Oecologia 85, 1-7. Gamon JA, Field CB, Fredeen A AL, Thayer S. 2001. Assessing photosynthetic downregulation in sunflower stands with an optically-based model. Photosynthesis Research 67, 113-125. Gamon JA, Peñuelas J, Field CB

  8. Reconstruction of full glacial environments and summer temperatures from Lago della Costa, a refugial site in Northern Italy

    NASA Astrophysics Data System (ADS)

    Samartin, Stéphanie; Heiri, Oliver; Kaltenrieder, Petra; Kühl, Norbert; Tinner, Willy

    2016-07-01

    Vegetation and climate during the last ice age and the Last Glacial Maximum (LGM, ∼23,000-19,000 cal BP) were considerably different than during the current interglacial (Holocene). Cold climatic conditions and growing ice-sheets during the last glaciation radically reduced forest extent in Europe to a restricted number of so-called ;refugia;, mostly located in the southern part of the continent. On the basis of paleobotanical analyses the Euganian Hills (Colli Euganei) in northeastern Italy have previously been proposed as one of the northernmost refugia of temperate trees (e.g. deciduous Quercus, Tilia, Ulmus, Fraxinus excelsior, Acer, Abies alba, Fagus sylvatica, Carpinus and Castanea) in Europe. In this study we provide the first quantitative, vegetation independent summer air temperature reconstruction for Northern Italy spanning the time ∼31,000-17,000 cal yr BP, which covers the coldest periods of the last glacial, including the LGM and Heinrich stadials 1 to 3. Chironomids preserved in a lake sediment core from Lago della Costa (7m a.s.l.), a small lake at the south-eastern edge of the Euganean Hills, allowed quantitative reconstruction of Full and Late Glacial summer air temperatures using a combined Swiss-Norwegian temperature inference model based on chironomid assemblages from 274 lakes. Chironomid and pollen evidence from Lago della Costa derives from finely stratified autochthonous organic gyttja sediments, which excludes major sediment mixing or reworking. After reconstructing paleo-temperatures, we address the question whether climate conditions were warm enough to permit the local survival of temperate tree species during the LGM and whether local expansions and pollen-inferred contractions of temperate tree taxa coincided with chironomid-inferred climatic changes. Our results suggest that chironomids at Lago della Costa have responded to major climatic fluctuations such as temperature decreases during the LGM and Heinrich stadials. The

  9. Linking carbon isotope signatures of nighttime leaf-respiratory and daytime assimilatory CO2 fluxes observed with laser spectrometry under field conditions

    NASA Astrophysics Data System (ADS)

    Gentsch, Lydia; Ogée, Jérôme; Wingate, Lisa; Sturm, Patrick; Siegwolf, Rolf; Werner, Roland A.; Buchmann, Nina; Knohl, Alexander

    2015-04-01

    The 13C/12C ratio (δ13C) of atmospheric CO2 is a valuable tool for constraining the impact of the terrestrial biosphere on atmospheric CO2 dynamics. Alterations of the 13C signal of terrestrial net CO2 fluxes are generally attributed to variations in photosynthetic 13C discrimination. Yet, over the past decade, evidence has emerged that plant metabolism and respiration modify the initial δ13C signature of recent photosynthetic assimilates. Such postphotosynthetic δ13C modifications were reported for all plant organs, but leaf respiratory metabolism may play a central role as it impacts carbon turnover in other plant tissues. Leaf-respired CO2 is frequently 13C enriched with respect to leaf organic matter. Mechanisms potentially explaining this enrichment include the differential use of carbon sources, metabolite fragmentation or the expression of kinetic isotope effects of respiratory enzymes. For global and ecosystem-scale applications of δ13C, it is now important to study, under field conditions, the variability of δ13C in leaf-respired CO2 (δ13CRES) and the deviation of the latter from δ13C of recent assimilates (δ13CAS). Here, we present 74 days of hourly δ13C measurements for daytime assimilatory and nighttime respiratory CO2 fluxes on leafy branches of three mature Fagus sylvatica trees in a temperate forest. Measurements were conducted with a laser spectrometer (QCLAS-ISO, Aerodyne Research Inc.) measuring CO2 isotopologue mixing ratios in ambient and sampling air from photosynthetic gas exchange chambers. We used daytime measurements of photosynthetic 13C discrimination for diurnally flux-weighted estimates of δ13CAS, and found that flux-weighted δ13CRES roughly tracked previous-day shifts in δ13CAS. Deviations between flux-weighted δ13CAS and δ13CRES were further robustly predicted by previous-day assimilation, with δ13CRES displaying 13C enrichment on low and 13C depletion on high assimilation days. On the hourly timescale, δ13CRES either

  10. The Influence of Tree Species on Subsurface Stormflow at the Hillslope Scale

    NASA Astrophysics Data System (ADS)

    Jost, G.; Weiler, M.

    2006-12-01

    This study investigates the effect of Norway spruce (Picea abies (L.) Karst) and European beech (Fagus sylvatica L.), two very common tree species in Central Europe, on soil water storage and runoff response to precipitation. We postulate that on the same type of soil, spruce with its shallow rooting system leads to different soil water storage and runoff responses than the deep rooting beech. To test this hypothesis, we chose a beech and a spruce stand with comparable soil type, a stagnic cambisol with a stagnic layer in about 50 cm soil depth. In each of the two stands we sprinkled a hillslope of 6 m by 10 m with intensities of 100 mm/h and 60 mm/h for one hour each. Surface and shallow interflow as well as interflow in different soil depths was collected by inserted sheet metals and gutters in 10 cm, 30 cm and 60 cm soil depth. Soil water storage responses were measured by 48 multiplexed TDR sensors at each hillslope. TDR wave-guides (20 cm long) were installed in a 45° angle in 10 cm, 30 cm, 50 cm and 70 cm soil depth. Volumetric water content was measured in 6 minute intervals. Sprinkling experiments show that even at intensities of 100 mm/h all the applied water infiltrates, independent of the vegetation cover. The deeper soil horizons respond immediately to the applied precipitation. This vertical water flux response is larger under beech. Under spruce most of the water transport happens in the topsoil layers (upper 40 cm), whereas under beech the entire soil profile down to 80 cm soil depth reacts to sprinkling. Under spruce at intensities of 100 mm/h the whole pore space is almost filled. The larger pores in the topsoil under beech stemming from higher biogenic activity and in the subsoil from more intense rooting are still far from reaching their maximum capacity. High antecedent soil water content (around field capacity) still doesn't cause infiltration excess overland flow but the time that it takes for the soil water storage to drain to its initial

  11. A hillslope scale comparison of tree species influence on soil moisture dynamics and runoff processes during intense rainfall

    NASA Astrophysics Data System (ADS)

    Jost, Georg; Schume, Helmut; Hager, Herbert; Markart, Gerhard; Kohl, Bernhard

    2012-02-01

    SummaryThis study investigates how different tree species influence soil hydrological properties that are relevant for the rainfall-runoff response of a given soil type. We hypothesize that for the same soil type, tree species that differ in rooting system, water consumption and associated soil fauna and soil flora lead to different soil moisture dynamics and lateral flow processes during rainfall and hence to different runoff responses. To test this hypothesis, we compare soil moisture patterns and interflow at different soil depths in a Norway spruce ( Picea abies (L.) Karst) forest and in a European beech ( Fagus sylvatica L.) forest during sprinkling experiments on two 6 × 10 m hillslope segments with the same soil type. Spruce with a shallow rooting system and sinkers that remain very shallow on poorly aerated soils and beech with a heart shaped, often deeper rooting system are two of the most important tree species in Central Europe. At each hillslope, volumetric soil water contents were measured in 6 min intervals with 48 TDR waveguides during and after sprinkling with intensities of 100 mm/h and 60 mm/h (for 1 h). The waveguides were installed in 12 soil pits, whereby a single soil pit consisted of four 20 cm buriable waveguides installed in 10 cm, 30 cm, 50 cm and 70 cm soil depth. Surface and shallow interflow at 10 cm soil depth and interflow at soil depths of 30 cm and 60 cm was automatically recorded. Despite the high rainfall intensities, no surface flow was observed in any of the experiments and only small amounts of shallow interflow were measured. Soil moisture patterns of lateral cross sections during and after the sprinkling reveal how tree species can alter runoff dynamics: under spruce, coinciding with rooting patterns, a water table develops in approximately 30 cm soil depth while the soil water content in 50 and 70 cm depth remains low. At the beech site, where coarse roots are found in deeper soil horizons, more water is directed towards

  12. An empirical study of the wound effects on sap flow measured with thermal dissipation probes

    NASA Astrophysics Data System (ADS)

    Wiedemann, Andreas; Marañón-Jiménez, Sara; Herbst, Mathias; Cuntz, Matthias; Rebmann, Corinna

    2014-05-01

    The eddy covariance technique allows the estimation of the evapotranspiration (evaporation and transpiration) at the stand level. Sap flow sensors have become widely used in combination with eddy covariance to assess the contribution of plant transpiration to the ecosystem evapotranspiration. Among the different techniques, the thermal dissipation (TD) is one of the most popular methods for sap flow measurements due to its straightforward use. As other methods, the TD technique implies a damage of the wood tissue, consequently changing wood thermal properties due to healing reactions. This may lead to an underestimation of sap flow and thus, to a lack of convergence with the ecosystem water flux at the ecosystem level measured by eddy covariance. However, the wound effect has not yet been experimentally assessed for the TD method. In this study we conducted an experiment to investigate the effect of wound healing on sap flux densities measured with TD probes. Our main goal is to establish specific correction factors for both ring-porous and diffuse-porous species, according to the time that passed since installation. Successive sets of TD probes were installed in early-, mid- and end-growing season in diffuse- and ring-porous trees (Fagus sylvatica and Quercus petraea) in order to test the effects of dynamic wound formation. The trees were cut in autumn and, afterwards, additional sets of sensors were installed in each stem segment, thus without wound reaction. Natural ranges of flux densities were applied through the segments in the laboratory and measured gravimetrically and by the TD sensors simultaneously. Gravimetric flow was then compared to the TD sensors with and without wound reactions. Preliminary results show that the utilization of the original calibration function, for sensors located in older measuring points (wounded tissue) measured lower sap flux densities than sensors installed after the tree harvest (without wound). Production of thick

  13. Tree species influence soil-atmosphere fluxes of the greenhouse gases CO2, CH4 and N2O

    NASA Astrophysics Data System (ADS)

    Steffens, Christina; Vesterdal, Lars; Pfeiffer, Eva-Maria

    2016-04-01

    In the temperate zone, forests are the greatest terrestrial sink for atmospheric CO2, and tree species affect soil C stocks and soil CO2 emissions. When considering the total greenhouse gas (GHG) balance of the forest soil, the relevant GHGs CH4 and N2O should also be considered as they have a higher global warming potential than CO2. The presented data are first results from a field study in a common garden site in Denmark where tree species with ectomycorrhizal colonization (beech - Fagus sylvatica, oak - Quercus robur) and with arbuscular mycorrhizal colonization (maple - Acer pseudoplatanus, ash - Fraxinus excelsior) have been planted in monocultures in adjacent blocks of about 0.25 ha in the year 1973 on former arable land. The soil-atmosphere fluxes of all three gases were measured every second week since August 2015. The hypothesis is that the total GHG efflux from forest soil would differ between species, and that these differences could be related to the type of mycorrhizal association and leaf litter quality. Preliminary results (August to December 2015) indicate that tree species influence the fluxes (converted to CO2-eq) of the three GHGs. Total soil CO2 efflux was in the low end of the range reported for temperate broadleaved forests but similar to the measurements at the same site approximately ten years ago. It was highest under oak (9.6±2.4 g CO2 m-2 d-1) and lowest under maple (5.2±1.6 g CO2 m-2 d-1). In contrast, soil under oak was a small but significant sink for CH4(-0.005±0.003 g CO2-eq m-2 d-1), while there were almost no detectable CH4 fluxes in maple. Emissions of N2O were highest under beech (0.6±0.6 g CO2-eq m-2 d-1) and oak (0.2±0.09 g CO2-eq m-2 d-1) and lowest under ash (0.03±0.04 g CO2-eq m-2 d-1). In the total GHG balance, soil CH4 uptake was negligible (≤0.1% of total emissions). Emissions of N2O (converted to CO2-eq) contributed <1% (ash) to 8% (beech) to total GHG emissions. Summing up all GHG emissions, the tree species

  14. A remote sensing tool to monitor and predict epidemiologic outbreaks of Hanta virus infections and Lyme disease

    NASA Astrophysics Data System (ADS)

    Barrios, J. M.

    2009-04-01

    Lyme disease and Hanta virus infection are the result of the conjunction of several climatic and ecological conditions. Although both affections have different causal agents, they share an important characteristic which is the fact that rodents play an important role in the contagium. One of the most important agents in the dispersion of these diseases is the bank vole (Clethrionomys glareoulus). The bank vole is a common host for both, the Borrelia bacteria which via the ticks (Ixodes ricinus) reaches the human body and causes the Lyme disease, and the Nephropatia epidemica which is caused by Puumala Hantavirus and affects kidneys in humans. The prefered habitat of bank voles is broad-leaf forests with an important presence of beeches (Fagus sylvatica) and oaks (Quercus sp.) and a relatively dense low vegetation layer. These vegetation systems are common in West-Europe and their dynamics have a great influence in the bank voles population and, therefore, in the spreading of the infections this study is concerned about. The fact that the annual seed production is not stable in time has an important effect in bank voles population and, as it has been described in other studies, in the number of reported cases of Hanta virus infections and Lyme disease. The years in which an abundant production of seeds is observed are referred to as mast years which are believed to obey to cyclic patterns and to certain climatological characteristics of the preceding years. Statistical analysis have confirmed the correlation in the behaviour of the number of infected cases and the presence of mast years. This project aims at the design of a remote sensing based system (INFOPRESS - INFectious disease Outbreak Prediction REmote Sensing based System) that should enable local and national health care instances to predict and locate the occurrence of infection outbreaks and design policies to counteract undesired effects. The predictive capabilities of the system are based on the

  15. A remote sensing tool to monitor and predict epidemiologic outbreaks of Hanta virus infections and Lyme disease

    NASA Astrophysics Data System (ADS)

    Barrios, M.; Verstraeten, W. W.; Amipour, S.; Wambacq, J.; Aerts, J.-M.; Maes, P.; Berckmans, D.; Lagrou, K.; van Ranst, M.; Coppin, P.

    2009-04-01

    Lyme disease and Hanta virus infection are the result of the conjunction of several climatic and ecological conditions. Although both affections have different causal agents, they share an important characteristic which is the fact that rodents play an important role in the contagion. One of the most important agents in the dispersion of these diseases is the bank vole (Clethrionomys glareoulus). The bank vole is a common host for both, the Borrelia bacteria which via the ticks (Ixodes ricinus) reaches the human body and causes the Lyme disease, and the Nephropatia epidemica which is caused by Puumala Hantavirus and affects kidneys in humans. The prefered habitat of bank voles is broad-leaf forests with an important presence of beeches (Fagus sylvatica) and oaks (Quercus sp.) and a relatively dense low vegetation layer. These vegetation systems are common in West-Europe and their dynamics have a great influence in the bank voles population and, therefore, in the spreading of the infections this study is concerned about. The fact that the annual seed production is not stable in time has an important effect in bank voles population and, as it has been described in other studies, in the number of reported cases of Hanta virus infections and Lyme disease. The years in which an abundant production of seeds is observed are referred to as mast years which are believed to obey to cyclic patterns and to certain climatologically characteristics of the preceding years. Statistical analysis have confirmed the correlation in the behaviour of the number of infected cases and the presence of mast years. This project aims at the design of a remote sensing based system (INFOPRESS - INFectious disease Outbreak Prediction REmote Sensing based System) that should enable local and national health care instances to predict and locate the occurrence of infection outbreaks and design policies to counteract undesired effects. The predictive capabilities of the system are based on the

  16. Linking carbon-water- and nitrogen fluxes at forest ecosystems throughout Europe with a coupled soil-vegetation process model "LandscapeDNDC"

    NASA Astrophysics Data System (ADS)

    Molina Herrera, Saul; Grote, Rüdiger; Haas, Edwin; Kiese, Ralf; Butterbach-Bahl, Klaus

    2013-04-01

    Forest ecosystems in Europe play a key role in the emission reduction commitment agreed in the Kyoto Protocol for mitigating climatic change. Forest ecological functioning and potential services (such as carbon sequestration) are a matter of debate for policy decision makers resulting from the need of identifying affordable strategies for forest management and exploitation against climate change. Forest ecosystem functioning and the linkages governing carbon-, water- and nitrogen fluxes at site scale was evaluated for three dominant tree species (Pinus sylvestris, Picea abies and Fagus sylvatica) grown on 10 different sites across Europe. We did answer in particular the following questions: a) is LandscapeDNDC able to represent NEE, GPP, TER and ET fluxes for dominant forest types in Europe at different sites with only a species specific parameterization? b) What is the relation between carbon input into the ecosystem and on the emission of carbon and nitrogen from the forest soil? Furthermore we analyzed the interaction between carbon-, nitrogen-, and water cycle, in particular the dependence of gaseous fluxes on water and litter availability. LandscapeDNDC is a process based model that integrates modules for carbon, nitrogen and water cycling within terrestrial ecosystems (i.e. forest) on the site and regional scale. Biosphere, atmosphere and hydrosphere processes in forest ecosystems are linked by daily time step integration of the microclimate, water cycle, soil biogeochemistry and tree physiology and dimensional growth modules which balances all three aforementioned cycles. All processes and state variables are considered in a vertically structured one dimensional vertical column that reaches from rooting depth (more than 1 m depth) to the uppermost canopy layer. LandscapeDNDC was tested against long term (about 10 years) field data. The capability of the applied model for reproducing daily derived GPP and TER was accompanied by a high statistical precision (r

  17. Carbon and Nitrogen dynamics in forest soils depending on light conditions and tree species

    NASA Astrophysics Data System (ADS)

    Veselinovic, Bojana; Hager, Herbert

    2013-04-01

    Climate change mitigation actions under the Kyoto Protocol apply among other decreases of CO2-emissions and/or increases of carbon (C) stocks. As soils represent the second biggest C-reservoir on Earth, an exact estimation of the stocks and reliable knowledge on C-dynamics in forest soils is of high importance. Anyhow, here, the accurate GHG-accounting, emission reductions and increase in C stocks is hampered due to lack of reliable data and solid statistical methods for the factors which influence C-sequestration in and its release from these systems. In spite of good progress in the scientific research, these factors are numerous and diverse in their interactions. This work focuses on influence of the economically relevant tree species - Picea abies, Fagus sylvatica and Quercus spp. - and light conditions on forest floor and mineral soil C and N dynamics in forest soils. Spruce monocultures have been widely used management practices in central European forests during the past century. Such stands are in lower altitudes and on heavy and water logged soils unstable and prone to disturbances, especially to windthrows. We hypothesize that windthrow areas loose C & N and that the establishment of the previous nutrient stocks is, if at all, only possible to be reached over the longer periods of time. We research also how the increased OM depletion affects the change of C & N stocks in forest floor vs. mineral soil. Conversion of such secondary spruce monocultures to site adequate beech and oak forests may enable higher stocks allocated predominantly as stable organic carbon and as plant available nitrogen. For this purpose sites at 300-700 m altitude with planosols were chosen in the region of the Northern Alpine Foothills. A false chronosequence approach was used in order to evaluate the impacts of the tree species and change in light conditions on dynamic of C & N in the forest floor and mineral soil, over the period 0-100 (for oak 120 y.) years. The C- and N

  18. Contrasting environmental memories by ancient soils on different parent rocks in the South-western Italian Alps

    NASA Astrophysics Data System (ADS)

    D'Amico, Michele; Catoni, Marcella; Bonifacio, Eleonora; Zanini, Ermanno

    2014-05-01

    Ancient soils (pre-Holocenic paleosols and vetusols) are uncommon on the Alps, because of the extensive Pleistocenic glaciations which erased most of the previously existing soils, the slope steepness and climatic conditions favoring soil erosion. However, in few sites, particularly in the outermost sections of the Alpine range, Pleistocene glaciers covered only small and scattered surfaces because of the low altitude reached in the basins, and ancient soils could be preserved for long periods of time on particularly stable surfaces. We described and sampled soils on 11 stable surfaces in the Upper Tanaro valley, Ligurian Alps (Southwestern Piemonte, Italy). The sampling sites were characterized by low steepness and elevation between 600 to 1600 m, under present day lower montane Castanea sativa/Ostrya carpinifolia forests, montane Fagus sylvatica and Pinus uncinata forests or montane heath/grazed grassland, on different substrata. In particular, we sampled soils developed on dolomite, limestone, quartzite, gneiss and shales. The soils were always well representative of the pedogenic trends active on the respective parent materials, i.e. the skeletal fraction in each soil was always composed of just one rock type, despite the proximity of lithological boundaries and the small dimensions of the different outcrops, often coexisting on the same stable surface. All the considered profiles showed signs of extremely long pedogenesis and/or different phases of intense pedogenesis interrupted by the deposition of periglacial cover beds in the steepest sites. Up to four phases of intense pedogenesis were recognized where cover beds were developed, presumably during cold Pleistocene phases, as present-day climate is not cold enough to create such periglacial morphologies. In such cases, each cover bed underwent similar pedogenesis, strongly dependent on the parent material: on quartzite, podzols with thick E horizons and well developed placic ones were formed in all phases

  19. Fluxes of CO2, CH4 and N2O at two European beech forests: linking soil gas production profiles with soil and stem fluxes

    NASA Astrophysics Data System (ADS)

    Maier, Martin; Machacova, Katerina; Halaburt, Ellen; Haddad, Sally; Urban, Otmar; Lang, Friederike

    2016-04-01

    consumption sites of soil gases in the adjacent soil. Soils at both sites took up CH4 and N2O and emitted CO2. Soil gas profiles at the Black Forest showed only CH4 and N2O consumption. CH4 uptake was much larger by the well aerated Black Forest soil than by the loamy-clay soil in the White Carpathians. Here, it was possible to stratify the apparently homogenous site into two plots, one having redoximorphic features in the soil profiles, the other plot without. It seemed that CH4 and N2O were mainly produced in the deeper soil at the plot with temporarily reducing conditions. Beech stems mostly took up N2O from the atmosphere at both sites, whereas CH4 was emitted. The stem CH4 flux was higher for the White Carpathians than for the Black Forest site. Thus, the tree and soil flux of CH4 seems to be affected by soil structure, soil water content and the redox potential in the rooting space. We conclude from our results that trees might provide preferential pathways for greenhouse gases produced in the subsoil thereby enhancing the release of greenhouse gases. Acknowledgement This research was financially supported by the Czech Academy of Sciences and the German Academic Exchange Service within the project "Methane (CH4) and nitrous oxide (N2O) emissions from Fagus sylvatica trees" (DAAD-15-03), National Programme for Sustainability I (LO1415) and project DFG (MA 5826/2-1). We would like to thank Marek Jakubik for technical support and Sinikka Paulus for help by field measurements.

  20. Effects of continuous cover forestry on soil moisture pattern - Beginning steps of a Hungarian study

    NASA Astrophysics Data System (ADS)

    Kalicz, Péter; Bartha, Dénes; Brolly, Gábor; Csáfordi, Péter; Csiszár, Ágnes; Eredics, Attila; Gribovszki, Zoltán; Király, Géza; Kollár, Tamás; Korda, Márton; Kucsara, Mihály; Nótári, Krisztina; Kornél Szegedi, Balázs; Tiborcz, Viktor; Zagyvai, Gergely; Zagyvai-Kiss, Katalin Anita

    2014-05-01

    Nowadays Hungarian foresters encounter a new challenge. The traditional management practices do not meet anymore with the demand of the civil society. The good old clearcut is no more a supported technology in forest regeneration. The transition to the continuous cover forestry induces much higher spatial variability compared to the even aged, more or less homogeneous, monoculture stands. The gap cutting is one of the proposed key methods in the Hungarian forestry. There is an active discussion among forest professionals how to determine the optimal gap size to maintain ideal conditions for the seedlings. Among other open questions for example how the surrounding trees modify the moisture pattern of the forest floor in the gap? In the early steps of a multidisciplinary project we established four research plots to study the spatial and temporal variability of soil moisture in the forest gap and the surrounding undisturbed stand. Each plot is located in oak (Quercus spp.) stands. Natural regeneration of oak stands is more problematic in our climate compared to the beech (Fagus sylvatica) which is located in the more humid or semi-humid areas of our country. All plots are located in the western part of Hungary: close to Sopron, Bejcgyertyános, Vép and Vajszló settlements. The last plot is an extensive research area, which is located in the riparian zone of a tributary of Feketevíz River. We monitor here the close-to-surface groundwater level fluctuation with pressure transducers. With a diurnal fluctuation based method it is possible to quantify the evapotranspiration differences between the gap and the stand. In two of the remaining stands (Bejcgyertyános and Vép) the gaps were opened in 2010. The monitoring of soil moisture began in 2013. A mobile sensor is used to monitor soil-moisture in a regular grid. The spatial variability of soil-moisture time-series shows a characteristic pattern during the growing-season. The plot in Sopron was established in 2013

  1. Effects of acute and chronic acidification on three larval amphibians that breed in temporary ponds

    SciTech Connect

    Rowe, C.L.; Sadinski, W.J.; Dunson, W.A. )

    1992-10-01

    This study explored the effects of acute (7 days) and chronic (4 months) exposure to pH 4.2 on three species of larval amphibians, Ambystoma jeffersonianum, Ambystoma maculatum, and Rana sylvatica. Acute tests were conducted in 24 impermeable enclosures in three temporary ponds. Total dissolved aluminum was higher in acidified enclosures in comparison with controls (pH 4.2, [Al] approximately 10-30 microM and pH greater than 4.7, [Al] approximately 5-15 microM, respectively). Greater mortality of A. jeffersonianum occurred at pH 4.2 than at pH greater than 4.7, whereas survival of A. maculatum and R. sylvatica were unaffected by pH. Mean wet masses of R. sylvatica were significantly lower at pH 4.2 than at pH greater than 4.7, but mean wet masses of surviving A. jeffersonianum and A. maculatum were not influenced by pH. There were no pH-related differences in body sodium concentration in larval R. sylvatica. Chronic acidification of mesocosms to pH 4.2 ([Al] approximately 16 microM) (controls = pH greater than 6, [Al] approximately 0.1 microM) resulted in total mortality of A. jeffersonianum. Survival of A. maculatum and R. sylvatica were not associated with pH, but survival of A. maculatum was low at both pH levels. Time to metamorphosis was longer for R. sylvatica maintained at pH 4.2, but not for A. maculatum. No differences in wet masses at metamorphosis were observed for R. sylvatica or A. maculatum. These results indicate that short and long term acidification of temporary wetlands could dramatically affect amphibians which rely upon them as breeding sites, either by causing mortality or by decreasing growth rates.

  2. Density of an intraguild predator mediates feeding group size, intraguild egg predation, and intra- and interspecific competition.

    PubMed

    Burley, Louise A; Moyer, Anna T; Petranka, James W

    2006-07-01

    Intraguild predation (IGP) is common in most communities, but many aspects of density-dependent interactions of IG predators with IG prey are poorly resolved. Here, we examine how the density of an IG predator can affect feeding group size, IG egg predation, and the growth responses of IG prey. We used laboratory feeding trials and outdoor mesocosm experiments to study interactions between a social intraguild predator (larvae of the wood frog; Rana sylvatica) and its prey (spotted salamander; Ambystoma maculatum). Larvae of R. sylvatica could potentially affect A. maculatum by consuming shared larval food resources or by consuming eggs and hatchlings. However, successful egg predation requires group feeding by schooling tadpoles. We established from five to 1,190 hatchlings of R. sylvatica in mesocosms, then added either 20 A. maculatum hatchlings to study interspecific competition, or a single egg mass to examine IGP. Crowding strongly suppressed the growth of R. sylvatica, and IGP was restricted to the egg stage. In the larval competition experiment, growth of A. maculatum was inversely proportional to R. sylvatica density. In the predation experiment, embryonic mortality of A. maculatum was directly proportional to the initial density of R. sylvatica and the mean number of tadpoles foraging on egg masses. IGP on eggs reduced A. maculatum hatchling density, which accelerated larval growth. Surprisingly, the density of R. sylvatica had no overall effect on A. maculatum growth because release from intraspecific competition via egg predation was balanced by increased interspecific competition. Our results demonstrate that the density of a social IG predator can strongly influence the nature and intensity of interactions with a second guild member by simultaneously altering the intensity of IGP and intra- and interspecific competition.

  3. Environmental Impact Research Program. Eastern Gray Squirrel (Sciurus carolinensis). Section 4.7.1, US Army Corps of Engineers Wildlife Resources Management Manual.

    DTIC Science & Technology

    1986-07-01

    Palmetto Sabal spp. Pawpaw Asimina triloba Pecan Carya illinoensis Persimmon Diospyros virginiana Pine Pinus app. Loblolly pine P. taeda Red mulberry...grandifotia Bitter pecan Carya aquatica Blackberry Rubus app. Black cherry Prunus serotina Blackgum Nyssa sylvatica Black walnut Jugtans nigra Blueberry...americana Hickory Carya Spp. Bitternut hickory C. cordiformis Shagbark hickory C. ovata Shellbark hickory C. Zaciniosa Hophornbeam Ostrya virginiana

  4. Ant and Mite Diversity Drives Toxin Variation in the Little Devil Poison Frog.

    PubMed

    McGugan, Jenna R; Byrd, Gary D; Roland, Alexandre B; Caty, Stephanie N; Kabir, Nisha; Tapia, Elicio E; Trauger, Sunia A; Coloma, Luis A; O'Connell, Lauren A

    2016-06-01

    Poison frogs sequester chemical defenses from arthropod prey, although the details of how arthropod diversity contributes to variation in poison frog toxins remains unclear. We characterized skin alkaloid profiles in the Little Devil poison frog, Oophaga sylvatica (Dendrobatidae), across three populations in northwestern Ecuador. Using gas chromatography/mass spectrometry, we identified histrionicotoxins, 3,5- and 5,8-disubstituted indolizidines, decahydroquinolines, and lehmizidines as the primary alkaloid toxins in these O. sylvatica populations. Frog skin alkaloid composition varied along a geographical gradient following population distribution in a principal component analysis. We also characterized diversity in arthropods isolated from frog stomach contents and confirmed that O. sylvatica specialize on ants and mites. To test the hypothesis that poison frog toxin variability reflects species and chemical diversity in arthropod prey, we (1) used sequencing of cytochrome oxidase 1 to identify individual prey specimens, and (2) used liquid chromatography/mass spectrometry to chemically profile consumed ants and mites. We identified 45 ants and 9 mites in frog stomachs, including several undescribed species. We also showed that chemical profiles of consumed ants and mites cluster by frog population, suggesting different frog populations have access to chemically distinct prey. Finally, by comparing chemical profiles of frog skin and isolated prey items, we traced the arthropod source of four poison frog alkaloids, including 3,5- and 5,8-disubstituted indolizidines and a lehmizidine alkaloid. Together, the data show that toxin variability in O. sylvatica reflects chemical diversity in arthropod prey.

  5. The use of artificial impoundments by two amphibian species in the Delaware Water Gap National Recreation Area

    USGS Publications Warehouse

    Julian, J.T.; Snyder, C.D.; Young, J.A.

    2006-01-01

    We compared breeding activity of Ambystoma maculatum (Spotted Salamander) and Rana sylvatica (Wood Frog) in artificial impoundments to patterns in natural wetlands over a three-year period in the Delaware Water Gap National Recreation Area. Rana sylvatica were 5.6 times more likely to use natural bodies of water for breeding than artificial impoundments, while A. maculatum were 2.7 times more likely to use natural bodies of water. Both species were approximately 9 times more likely to breed in fishless bodies of water than in waters with predatory fish. Ambystoma maculatum were 6 times more likely to breed in wetlands with more stable seasonal hydroperiods, while R. sylvatica were only 2 times more likely to do so. We conclude that the high likelihood of fish presence in impoundments was the primary explanation for why both species were less likely to use impoundments than natural wetlands, while the tendency of A. maculatum to avoid natural wetlands with shorter hydroperiods explained why differences in use between pond types was more pronounced for R. sylvatica.

  6. Ste. Genevieve, Missouri Feasibility Report (Flood Control Study for Historic Ste. Genevieve - 80061). Volume 2. Appendices.

    DTIC Science & Technology

    1984-06-01

    Group Common Name Habitat Status Plants Bassania trilobata Liverwort shaded sandstone, Endangered base of cliff ’.Br~yoxipu Sword Moss on shaded...floors bordering streams Marsupella Liverwort shaded sandstone Endangered sullivantii where seepage is abundant % F- 13 Group Common Name Habitat Status...Microlepidozia Liverwort in crevices of Endangered sylvatica sandstone Mimulus &labratius Monkey Flower springs & wet ledges Rare var fremontii along

  7. Effect on a long-term afforestation of pine in a beech domain in NE-Spain as reflected in soil C and N isotopic signature

    NASA Astrophysics Data System (ADS)

    Girona García, Antonio; Badía-Villas, David; González-Pérez, José Antonio; Tomás Jiménez-Morillo, Nicasio; Martí-Dalmau, Clara

    2015-04-01

    The replacement of native beech forests (Fagus sylvatica) by Scots pine (Pinus sylvestris) afforestation may exert changes in soil properties, particularly in soil organic matter (SOM) (Carceller and Vallejo, 1996). Stable isotopic signatures of light elements (d13C, d15N) in soils and plants are valuable proxies for the identification of biogeochemical processes and their rates in the pedosphere (Andreeva et al., 2013 and refs therein). In this work the C and N stable isotopic analysis is used as a proxy to detect changes in SOM surrogated to the effect of centennial replacement of beech by the Scots pinewood. Two acid soil profiles, developed on quartzites under a humid climate at an altitude of 1400-1500 masl, have been sampled in Moncayo (Iberian range, NE-Spain). For each soil profile three O-layers (litter: OL, fragmented litter OF and humified litter OH) and mineral soil horizons (Ah, E, Bhs and C) were sampled. Content and bulk isotopic signature of light elements (C and N) were analysed in a Flash 2000 elemental micro-analyser coupled via a ConFlo IV interface to a Delta V Advantage isotope ratio mass spectrometer (IRMS) (Thermo Scientific, Bremen, Germany). Isotopic ratios are reported as parts per thousand deviations from appropriate standards. The standard deviations of d13C and d15N were typically less than ± 0.05 per thousand, ± 0.2 per thousand, respectively. After 100 years since the pine afforestation, no differences on C content were observed in the O-layers, ranging from 30-47% in pine soils and 37-47 % in beech soils. Similarly, no differences on N content were observed in the O-layers, ranging from 1.24-1.86 % in pine soils and 1.70-1.71 % in beech soils. C and N contents decrease progressively in depth with the exception of E-horizons where the lowest C and N content values were found. C/N ratio is higher in pine soil (20.7-38.1) than in beech O soil horizons (21.8-27.5), showing similar behavior with soil depth. Pine biomass was slightly

  8. Tuning the voices of a choir: Introducing a new tool to enhance the signals that are stored in tree-ring archives

    NASA Astrophysics Data System (ADS)

    Buras, Allan; van der Maaten, Ernst; Scharnweber, Tobias; Simard, Sonia; Heinrich, Ingo; Helle, Gerd; van der Maaten-Theunissen, Marieke; Eusemann, Pascal; Schnittler, Martin; Wilmking, Martin

    2015-04-01

    datasets WPCA resulted in a continuum of tree growth responses and was thus able to identify individual growth responses. To allow for a definition of groups based upon WPCA, we combined EPS with the Subsample Signal Strength (SSS), which allows for predicting the EPS of a population subsample (Wigley et al., 1984). If individual growth responses existed, EPS of WPCA defined subsamples was higher as expected from the SSS prediction, though it was lower than the overall EPS. Average chronologies of groups defined by WPCA expressed much stronger responses to particular environmental parameters and thus a much higher potential for environmental reconstruction in comparison with the overall, site based, master chronology. With respect to the other studied approaches, WPCA appeared to be advantageous as it needs less a priori assumptions. Based on our analyses we conclude that WPCA allows for a more precise tuning of tree-ring based reconstructions and therefore is able to enhance the precision of estimates on past environmental conditions. In contrast, a rigorous maximization of EPS as frequently undertaken in many studies may even decrease the quality of environmental reconstructions if individual growth responses exist. As a consequence we suggest the application of WPCA prior to any tree-ring based reconstructions to maximize the precision of palaeo-environment reconstructions. Carrer, M., 2011. Individualistic and time-varying tree-ring growth to climate sensitivity. PLoS ONE 6, e22813. Fritts, H.C., 1976. Tree rings and climate. Academic Press, London. Piovesan, G., Biondi, F., Di Filippo, A., Alessandrini, A., Maugeri, M., 2008. Drought-driven growth reduction in old beech (Fagus sylvatica L.) forests of the central Apennines, Italy. Glob. Change Biol. 14, 1265-1281. Walker, X., Johnstone, J.F., 2014. Widespread negative correlations between black spruce growth and temperature across topographic moisture gradients in the boreal forest. Environ. Res. Lett. 9, 064016

  9. Effect of a long-term afforestation of pine in a beech domain in NE-Spain revealed by analytical pyrolysis (Py-GC/MS)

    NASA Astrophysics Data System (ADS)

    Girona García, Antonio; Badía-Villas, David; Tomás Jiménez-Morillo, Nicasio; Martí-Dalmau, Clara; González-Pérez, José Antonio

    2015-04-01

    The replacement of native beech forests (Fagus sylvatica) by Scots pine (Pinus sylvestris) afforestation may exert changes in soil properties, particularly in soil organic matter (SOM) [1]. It is known that the products generated by Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) pyrolysis of organic matter are related to their origin [2 and references therein]. Therefore this technique can be used to investigate said changes. In this work, Py-GC/MS is used to study changes in SOM quality surrogated to the effect of the centennial replacement of beech by Scots pine. The soils studied were two acid soil profiles developed on quartzites under a humid climate at an altitude of 1400-1500 masl from Moncayo (Iberian range, NE-Spain). For each soil profile three organic layers (litter: OL, fragmented litter OF and humified litter OH) and the mineral soil horizons (Ah, E, Bhs and C) were sampled. After 100 years since the pine afforestation, differences in the relative abundance of lipids released by pyrolysis were observed in the O-layers ranging from 3.82-7.20% in pine soils and 0.98-1.25% in beech soils. No differences were observed in mineral horizons with depth except for the C horizons where beech lipid content was much higher (21.25%) than in that under pine (1.07%). Both pine and beech soils show similar nitrogen compounds relative contents along the soil profile, increasing from OL to Ah (3.49-9.11% and 2.75-11.73% in beech and pine respectively) with a conspicuous reduction in the E horizon. It is remarkable the absence of nitrogen compounds in beech Bhs and C horizons. The relative content of aromatic compounds in O-layers show opposite trends for beech and pine; an enrichment in aromatic compounds is observed in beech OL layer (12.39%) decreasing to 4.11% in OH layer in contrast, whereas for pine O-layers the aromatic compounds relative abundance was higher in the OH (5.83%) than in the OL layer (2.8%). Mineral Ah and E horizons show similar values in

  10. The impact of atmospheric deposition and climate on forest growth in Europe using two empirical modelling approaches

    NASA Astrophysics Data System (ADS)

    Dobbertin, M.; Solberg, S.; Laubhann, D.; Sterba, H.; Reinds, G. J.; de Vries, W.

    2009-04-01

    Most recent studies show increasing forest growth in central Europe, rather than a decline as was expected due to negative effects of air pollution. While nitrogen deposition, increasing temperature and change in forest management are discussed as possible causes, quantification of the various environmental factors has rarely been undertaken. In our study, we used data from several hundreds of intensive monitoring plots from the ICP Forests network in Europe, ranging from northern Finland to Spain and southern Italy. Five-year growth data for the period 1994-1999 were available from roughly 650 plots to examine the influence of environmental factors on forest growth. Evaluations focused on the influence of nitrogen, sulphur and acid deposition, temperature, precipitation and drought. Concerning the latter meteorological variables we used the deviation from the long-term (30 years) mean. The study included the main tree species common beech (Fagus sylvatica), sessile or pedunculate oak (Quercus petraea and Q. robur), Scots pine (Pinus sylvestris) and Norway spruce (Picea abies). Two very different approaches were used. In the first approach an individual tree-based regression model was applied (Laubhahn et al., 2009), while in the second approach a stand-based model was applied (Solberg et al., 2009). The individual tree-based model had measured basal area increment of each individual tree as a growth response variable and tree size (diameter at breast height), tree competition (basal area of larger trees and stand density index), site factors (e.g. soil C/N ratio, temperature), and environmental factors (e.g. temperature change compared to long-term average, nitrogen and sulphur deposition) as influencing parameters. In the stand-growth model, stem volume increment was used as the growth response variable, after filtering out the expected growth. Expected growth was modelled as a function of site productivity, stand age and a stand density index. Relative volume

  11. Relationship between the Decomposition Process of Coarse Woody Debris and Fungal Community Structure as Detected by High-Throughput Sequencing in a Deciduous Broad-Leaved Forest in Japan

    PubMed Central

    Yamashita, Satoshi; Masuya, Hayato; Abe, Shin; Masaki, Takashi; Okabe, Kimiko

    2015-01-01

    We examined the relationship between the community structure of wood-decaying fungi, detected by high-throughput sequencing, and the decomposition rate using 13 years of data from a forest dynamics plot. For molecular analysis and wood density measurements, drill dust samples were collected from logs and stumps of Fagus and Quercus in the plot. Regression using a negative exponential model between wood density and time since death revealed that the decomposition rate of Fagus was greater than that of Quercus. The residual between the expected value obtained from the regression curve and the observed wood density was used as a decomposition rate index. Principal component analysis showed that the fungal community compositions of both Fagus and Quercus changed with time since death. Principal component analysis axis scores were used as an index of fungal community composition. A structural equation model for each wood genus was used to assess the effect of fungal community structure traits on the decomposition rate and how the fungal community structure was determined by the traits of coarse woody debris. Results of the structural equation model suggested that the decomposition rate of Fagus was affected by two fungal community composition components: one that was affected by time since death and another that was not affected by the traits of coarse woody debris. In contrast, the decomposition rate of Quercus was not affected by coarse woody debris traits or fungal community structure. These findings suggest that, in the case of Fagus coarse woody debris, the fungal community structure is related to the decomposition process of its host substrate. Because fungal community structure is affected partly by the decay stage and wood density of its substrate, these factors influence each other. Further research on interactive effects is needed to improve our understanding of the relationship between fungal community structure and the woody debris decomposition process

  12. Relationship between the decomposition process of coarse woody debris and fungal community structure as detected by high-throughput sequencing in a deciduous broad-leaved forest in Japan.

    PubMed

    Yamashita, Satoshi; Masuya, Hayato; Abe, Shin; Masaki, Takashi; Okabe, Kimiko

    2015-01-01

    We examined the relationship between the community structure of wood-decaying fungi, detected by high-throughput sequencing, and the decomposition rate using 13 years of data from a forest dynamics plot. For molecular analysis and wood density measurements, drill dust samples were collected from logs and stumps of Fagus and Quercus in the plot. Regression using a negative exponential model between wood density and time since death revealed that the decomposition rate of Fagus was greater than that of Quercus. The residual between the expected value obtained from the regression curve and the observed wood density was used as a decomposition rate index. Principal component analysis showed that the fungal community compositions of both Fagus and Quercus changed with time since death. Principal component analysis axis scores were used as an index of fungal community composition. A structural equation model for each wood genus was used to assess the effect of fungal community structure traits on the decomposition rate and how the fungal community structure was determined by the traits of coarse woody debris. Results of the structural equation model suggested that the decomposition rate of Fagus was affected by two fungal community composition components: one that was affected by time since death and another that was not affected by the traits of coarse woody debris. In contrast, the decomposition rate of Quercus was not affected by coarse woody debris traits or fungal community structure. These findings suggest that, in the case of Fagus coarse woody debris, the fungal community structure is related to the decomposition process of its host substrate. Because fungal community structure is affected partly by the decay stage and wood density of its substrate, these factors influence each other. Further research on interactive effects is needed to improve our understanding of the relationship between fungal community structure and the woody debris decomposition process.

  13. Microcosm investigations of stormwater pond sediment toxicity to embryonic and larval amphibians: variation in sensitivity among species.

    PubMed

    Snodgrass, Joel W; Casey, Ryan E; Joseph, Debra; Simon, Judith A

    2008-07-01

    Stormwater ponds have become common features of modern development and often represent significant amounts of open space in urbanized areas. Although stormwater ponds may provide habitat for wildlife, factors responsible for producing variation in wildlife use of ponds have received limited attention. To investigate the role of variation in species tolerances of pollutants in structuring pond-breeding amphibian assemblages, we exposed species tolerant (Bufo americanus) and not tolerant (Rana sylvatica) of urbanization to pond sediments in laboratory microcosms. Pond microcosms had elevated sediment metal levels and chloride water concentrations. Among R. sylvatica embryos, exposure to pond sediments resulted in 100% mortality. In contrast, B. americanus embryos and larvae experienced only sublethal effects (i.e., reduced size at metamorphosis) due to pond sediment exposure. Our results suggest variation in pollutant tolerance among early developmental stages of amphibians may act in concert with terrestrial habitat availability to structure amphibian assemblages associated with stormwater ponds.

  14. Leopard frog and wood frog reproduction in Colorado and Wyoming

    USGS Publications Warehouse

    Corn, Paul Stephen; Livo, Lauren J.

    1989-01-01

    Between 1978 and 1988, we recorded reproductive information from populations of ranid frogs in Colorado and Wyoming. Egg masses from five plains and montane populations of northern leopard frogs (Rana pipiens) contained 645-6272 eggs (x̄ = 3045, N = 68 egg masses). In two montane populations of wood frogs (Rana sylvatica) numbers of eggs per egg mass varied from 711-1248 (x̄ = 876, N = 15) and probably were equal to total clutch size. Mean hatching success was 90% in egg masses from one R. sylvatica population and ranged from 70% to 99% in R. pipiens egg masses. Rana pipiens egg masses from one location were assigned to three overlapping size distributions, which we believe reflects the underlying age structure of female frogs.

  15. The Buffalo Creek Archaeological Project. Volume 1: Background and Testing at 3MS346 and 3CG847 Mississippi and Craighead Counties, Arkansas

    DTIC Science & Technology

    1992-01-01

    shagbark hickory ( Carya ovata), and pecan ( Carya illinoensis ). These trees dominate the vegetation on well-drained elevated land such as tho-se areas...strongly acidic soil (Steyermark 1959:95, 120). Chinquapin (Castanea ozarkensis), black or sourgum (Nyssa sylvatica), black hickory ( Carya texana...white oak, mockernut hickory ( Carya tomentosa), black hickory, white hickory ( Carya alba), flowering dogwoo-T-,whiT𔃻eFash(Fraxinus americana

  16. Impacts of road deicing salt on the demography of vernal pool-breeding amphibians.

    PubMed

    Karraker, Nancy E; Gibbs, James P; Vonesh, James R

    2008-04-01

    Deicing agents, primarily road salt, are applied to roads in 26 states in the United States and in a number of European countries, yet the scale of impacts of road salt on aquatic organisms remains largely under-studied. The issue is germane to amphibian conservation because both adult and larval amphibians are known to be particularly sensitive to changes in their osmolar environments. In this study, we combined survey, experimental, and demographic modeling approaches to evaluate the possible effects of road salt on two common vernal-pond-breeding amphibian species, the spotted salamander (Ambystoma maculatum) and the wood frog (Rana sylvatica). We found that in the Adirondack Mountain Region of New York (USA), road salt traveled up to 172 m from the highway into wetlands. Surveys showed that egg mass densities of spotted salamanders (A. maculatum) and wood frogs (R. sylvatica) were two times higher in forest pools than roadside pools, but this pattern was better explained by road proximity than by increased salinity. Experiments demonstrated that embryonic and larval survival were reduced at moderate (500 muS) and high conductivities (3000 muS) in A. maculatum and at high conductivities in R. sylvatica. Demographic models suggest that such egg and larval stage effects of salt may have important impacts on populations near roads, particularly in the case of A. maculatum, for which salt exposure may lead to local extinction. For both species, the effect of road salt was dependent upon the strength of larval density dependence and declined rapidly with distance from the roadside, with the greatest negative effects being limited to within 50 m. Based on this evidence, we argue that efforts to protect local populations of A. maculatum and R. sylvatica in roadside wetlands should, in part, be aimed at reducing application of road salt near wetlands with high conductivity levels.

  17. The Mattassee Lake Sites: Archeological Investigations Along the Lower Santee River in the Coastal Plain of South Carolina.

    DTIC Science & Technology

    1982-12-01

    340 .- q Fourteen taxa were identified: Woodland features at site 38BK246 yielded GRAMINEAE (Grass family), CYPERACEAE blackberry and dogwood. ( sedge ... sedge , pickerelweed, bayberry and Nyssa or Biplisia spp.), and grape seed (Widmer spp. (if this is tupelo, N. sylvatica). 1976a:36). The seeds were...with the swamp or swamp margin, including americana (poke), Rubus spp. (blackberry), sedge , pickerelweed, bayberry and possibly LEGUMICOSAE (Bean family

  18. Physiological responses of freeze-tolerant and -intolerant frogs: clues to evolution of anuran freeze tolerance.

    PubMed

    Costanzo, J P; Lee, R E; Lortz, P H

    1993-10-01

    Freeze tolerance in the wood frog, Rana sylvatica, is promoted by multiple, integrated physiological responses to ice forming within body tissues. By analyzing the freezing responses of the sympatric, but freeze intolerant, leopard frog (R. pipiens), we sought clues to the evolution of anuran freeze tolerance. Physiological responses critical to R. sylvatica's freeze tolerance, such as the synthesis and distribution of the cryoprotectant glucose, protective dehydration of organs, and deferred cardiac failure, were present, but comparatively less pronounced, in R. pipiens. Both species were innately tolerant of hyperglycemia. Glucose supplements did not enhance the freezing viability of R. pipiens, although in vitro tests of cryoprotectant efficacy revealed that glucose and glycerol provided comparable protection to erythrocytes of both species. We conclude that the evolution of freeze tolerance in R. sylvatica is not only promoted by its desiccation tolerance and the fortuitous biophysical consequences of freezing (e.g., exothermic induction of cardioacceleration and moderation of cooling rate) but also involves a progressive enhancement of fundamental physiological stress responses.

  19. Assessment of tree toxicity near the F- and H-Area seepage basins of the Savannah River Site

    SciTech Connect

    Loehle, C. ); Richardson, C.J.; Greenwood, K.P.; Hane, M.E.; Lander, A.J. )

    1990-12-01

    Areas of tree mortality, originating in 1979, have been documented downslope of the F- and H-Area Seepage Basins. The basins were used as discharge areas for low-level radioactive and nonradioactive waste. Preliminary studies indicated that there are three possible causes of stress: altered hydrology; hazardous chemicals; and nonhazardous chemicals. It was originally hypothesized that the most likely hydrological stressors to Nyssa sylvatica var. biflora were flooding where water levels cover the lenticels for more than 26 percent of the growing season, resulting in low oxygen availability, and toxins produced under anaerobic conditions. In fact, trees began to show stress only flowing a drought year (1977) rather than a wet year. Dry conditions could exacerbate stress by concentrating contaminants, particularly salt. Study of the soil and water chemical parameters in the impacted sites indicated that salt concentrations in the affected areas have produced abnormally high exchangeable sodium percentages. Furthermore, significantly elevated concentrations of heavy metals were found in each impacted site, although no one metal was consistently elevated. Evaluation of the concentrations of various chemicals toxic to Nyssa sylvatica var. biflora revealed that aluminum was probably the most toxic in the F-Area. Manganese, cadmium, and zinc had concentrations great enough to be considered possible causes of tree mortality in the F-Area. Aluminum was the most likely cause of mortality in the H-Area. Controlled experiments testing metal and salt concentration effects on Nyssa sylvatica would be needed to specifically assign cause and effect mortality relationships.

  20. Health evaluation of amphibians in and near Rocky Mountain National Park (Colorado, USA)

    USGS Publications Warehouse

    Green, D.E.; Muths, E.

    2005-01-01

    We conducted a health survey of amphibians in and adjacent to Rocky Mountain National Park (RMNP) to document current disease presence inside RMNP and identify disease outside RMNP with the potential to spread to the Park's amphibians. Amphibians from five sites within RMNP and seven sites within 60 km of Park boundaries were collected and examined. Necropsies (n - 238), virus isolation, bacterial and fungal cultures, and histological examinations were carried out on amphibian egg masses (outside RMNP/within RMNP: 26/22), larvae (30/42), imagos (recently metamorphosed individuals) (0/3) and adults (61/67) of five species. Marked infections by a pathogenic chytrid fungus (chyridiomycosis), Batrachochytrium dendrobatidis, were detected in three species (Bufo boreas, Pseudacris maculata and Rana sylvatica) from three of five sites within RMNP and in one of three species (P. maculata) from three sites outside RMNP. Of the fully metamorphosed individuals tested (B. boreas, P. maculata and R. sylvatica), chytridiomycosis was found in 60 % (n = 3), 46 % (n = 37) and 54 % (n = 7), respectively. Chytridiomycosis was the principal lethal pathogenic infectious disease detected in three amphibian species within or adjacent to RMNP. Higher fungi were isolated from the cloaca and skin of all five amphibian species. Watermolds (Oomycetes) were isolated from amphibian eggs or skin of all five species. No evidence of Ranavirus was found in cultures and histological examinations of 176 and 142 amphibians, respectively. Fifteen genera of bacteria were identified in larval and just metamorphosed amphibians, and a potentially pathogenic lungworm, Rhabdias sp, was identified in 61.1 % (n = 11) of B. woodhousii outside RMNP, but in only 2 (15.4 %) R. sylvatica within the Park.

  1. Zulu medicinal plants with antibacterial activity.

    PubMed

    Kelmanson, J E; Jäger, A K; van Staden, J

    2000-03-01

    Aqueous, methanolic and ethyl acetate extracts of 14 plants used in traditional Zulu medicine for treatment of ailments of an infectious nature were screened for antibacterial activity. Most of the activity detected was against gram-positive bacteria. Tuber bark extracts of Dioscorea sylvatica had activity against gram-negative Escherichia coli and extracts of Dioscorea dregeana, Cheilanthes viridis and Vernonia colorata were active against Pseudomonas aeruginosa. The highest antibacterial activity was found in extracts of C. viridis, D. dregeana, D. silvatica, Melianthus comosus and V. colorata. In general, methanolic extracts exhibited higher activity than aqueous and ethyl acetate extracts.

  2. Evaluation of the anti-mycobacterium tuberculosis activity and in vivo acute toxicity of Annona sylvatic

    PubMed Central

    2014-01-01

    Background The recent emergence of extensively multidrug-resistant Mycobacterium tuberculosis strains has further complicated the control of tuberculosis. There is an urgent need for the development of new molecular candidates antitubercular drugs. Medicinal plants have been an excellent source of leads for the development of drugs. The aim of this study was to evaluate the in vitro activity of 28 alcoholic extracts and essential oils of native and exotic Brazilian plants against Mycobacterium tuberculosis and to further study these extracts through chemical fractionation, the isolation of their constituents, and an evaluation of the in vivo acute toxicity of the active extracts. To the best of our knowledge this is the first chemical characterization, antituberculosis activity and acute toxicity evaluation of Annona sylvatica. Methods The anti-mycobacterial activity of these extracts and their constituent compounds was evaluated using the resazurin reduction microtiter assay (REMA). To investigate the acute toxicity of these extracts in vivo, female Swiss mice were treated with the extracts at doses of 500, 1000 and 2000 mg · kg-1 of body weight. The extracts were characterized by LC-MS, and the constituents were isolated and identified by chromatographic analysis of spectroscopic data. Results Of the 28 extracts, the methanol extract obtained from the leaves of Annona sylvatica showed anti-mycobacterial activity with an minimal inhibitory concentration (MIC) of 184.33 μg/mL, and the ethyl acetate fraction (EAF) resulting from liquid-liquid partitioning of the A. sylvatica extract showed an MIC of 115.2 μg/mL. The characterization of this extract by LC-MS identified flavonoids and acetogenins as its main constituents. The phytochemical study of the A. sylvatica EAF resulted in the isolation of quercetin, luteolin, and almunequin. Conclusions Among the compounds isolated from the EAF, luteolin and almunequin were the most promising, with MICs of 236.8

  3. Tree branching: Leonardo da Vinci's rule versus biomechanical models.

    PubMed

    Minamino, Ryoko; Tateno, Masaki

    2014-01-01

    This study examined Leonardo da Vinci's rule (i.e., the sum of the cross-sectional area of all tree branches above a branching point at any height is equal to the cross-sectional area of the trunk or the branch immediately below the branching point) using simulations based on two biomechanical models: the uniform stress and elastic similarity models. Model calculations of the daughter/mother ratio (i.e., the ratio of the total cross-sectional area of the daughter branches to the cross-sectional area of the mother branch at the branching point) showed that both biomechanical models agreed with da Vinci's rule when the branching angles of daughter branches and the weights of lateral daughter branches were small; however, the models deviated from da Vinci's rule as the weights and/or the branching angles of lateral daughter branches increased. The calculated values of the two models were largely similar but differed in some ways. Field measurements of Fagus crenata and Abies homolepis also fit this trend, wherein models deviated from da Vinci's rule with increasing relative weights of lateral daughter branches. However, this deviation was small for a branching pattern in nature, where empirical measurements were taken under realistic measurement conditions; thus, da Vinci's rule did not critically contradict the biomechanical models in the case of real branching patterns, though the model calculations described the contradiction between da Vinci's rule and the biomechanical models. The field data for Fagus crenata fit the uniform stress model best, indicating that stress uniformity is the key constraint of branch morphology in Fagus crenata rather than elastic similarity or da Vinci's rule. On the other hand, mechanical constraints are not necessarily significant in the morphology of Abies homolepis branches, depending on the number of daughter branches. Rather, these branches were often in agreement with da Vinci's rule.

  4. Some important physical properties of laminated veneer lumber (Lvl) made from oriental beech and Lombardy poplar

    NASA Astrophysics Data System (ADS)

    Kılıç, Murat

    2012-09-01

    This study examined some physical characteristics of laminated veneer lumber (LVL) obtained in different compositions from cut veneers of Oriental beech (Fagus Orientalis Lipsky) and Lombardy poplar (Populus nigra) with thicknesses of 4 mm and 5 mm. Five each beech and poplar trees were felled with this objective. The PVAc (Kleiberit 303) and PU (Bizon Timber PU-Max Express) types of adhesive were used in lamination. The air-dry and oven dry densities, cell wall density and porosity, the value of volume density, shrinkage in a tangential and radial direction and volume swelling amounts were determined by preparing the specimens in accordance with the standards.

  5. A new species of Mollitrichosiphum Suenaga from Taiwan Island (Hemiptera, Aphididae), based on morphological characteristics and DNA sequences

    PubMed Central

    Jiang, Li-Yun; Chen, Jing; Qiao, Ge-Xia

    2015-01-01

    Abstract A new species of Mollitrichosiphum Suenaga, Mollitrichosiphum tumorisiphum Qiao & Jiang, sp. n., from Fagus longipetiolata in Taiwan island is described. Siphunculi of Mollitrichosiphum tumorisiphum in alatae are distinctly swollen on the distal part, unlike those of the other known species in the genus. Updated keys to apterous and alate viviparous females of all known Chinese species of Mollitrichosiphum are provided. The specimens studied are deposited in the National Zoological Museum of China, Institute of Zoology, Chinese Academy of Sciences, Beijing, China and the Natural History Museum, London, United Kingdom. PMID:26478705

  6. Interrelation between some butterflies and plant associations (Turkey).

    PubMed

    Ozdemir, M; Seven, S

    2007-01-01

    The butterfly fauna in Ordu province (N-Turkey) was determined in this study. Their relations with the phytosociological associations found in the zone were evaluated and the Lepidoptera taxa in these units were presented. The numbers of determined taxa in each plant association are Castanea-Carpinus-Corylus (23), Fagus orientalis, Carpinus betulus and Picea orientalis Mixed Forest Zone (23), Subalpine Zone (Rhododendron luteum-Vaccinium myrtillus) (25), Lower Alpine Zone (Festuca lazistanica ssp. giresunica) (20), Mid-alpine Zone (Festuca lazistanica ssp. giresunica) (13). Fifteen taxa are new for Ordu province.

  7. Cuticular Compounds Bring New Insight in the Post-Glacial Recolonization of a Pyrenean Area: Deutonura deficiens Deharveng, 1979 Complex, a Case Study

    PubMed Central

    Porco, David; Bedos, Anne; Deharveng, Louis

    2010-01-01

    Background In most Arthropod groups, the study of systematics and evolution rely mostly on neutral characters, in this context cuticular compounds, as non-neutral characters, represent an underexplored but potentially informative type of characters at the infraspecific level as they have been routinely proven to be involved in sexual attraction. Methods and Findings The collembolan species complex Deutonura deficiens was chosen as a model in order to test the utility of these characters for delineating four infraspecific entities of this group. Specimens were collected for three subspecies (D. d. deficiens, D. d. meridionalis, D. d. sylvatica) and two morphotypes (D. d. sylvatica morphoype A and B) of the complex; an additional species D. monticola was added. Cuticular compounds were extracted and separated by gas chromatography for each individual. Our results demonstrate that cuticular compounds succeeded in separating the different elements of this complex. Those data allowed also the reconstruction of the phylogenetic relationships among them. Conclusions The discriminating power of cuticular compounds is directly related to their involvement in sexual attraction and mate recognition. These findings allowed a discussion on the potential involvement of intrinsic and paleoclimatic factors in the origin and the diversification of this complex in the Pyrenean zone. This character type brings the first advance from pattern to process concerning the origin of this species complex. PMID:21209797

  8. Frog virus 3-like infections in aquatic amphibian communities.

    PubMed

    Duffus, A L J; Pauli, B D; Wozney, K; Brunetti, C R; Berrill, M

    2008-01-01

    Frog virus 3 (FV3) and FV3-like viruses, are members of the genus Ranavirus (family Iridoviridae), and they have been associated with infectious diseases that may be contributing to amphibian population declines. We examined the mode of transmission of an FV3-like virus, and potential hosts and reservoirs of the virus in a local amphibian community. Using the polymerase chain reaction to detect infected animals, we found an FV3-like virus in south-central Ontario, Canada, amphibian communities, where it infects sympatric amphibian species, including ranid and hylid tadpoles (Rana sylvatica, Hyla versicolor, and Pseudacris spp.), larval salamanders (Ambystoma spp.), and adult eastern-spotted newts (Notophthalmus viridescens). The high prevalence of FV3-like infections in caudate larvae suggests that salamanders are likely to be both hosts and reservoirs. In laboratory FV3 challenges of R. sylvatica, the rate of infection was dependent on the amount of virus to which the animals were exposed. In addition, although vertical transmission was suspected, horizontal transmission through exposure to infected pond water is the most likely route of infection in tadpoles. Based on our observations, a simple model of FV3/FV3-like virus transmission postulates that, in aquatic amphibian communities, transmission of the virus occurs between anuran and urodele species, with ambystomatid salamanders the most likely reservoir for the ranavirus in our study.

  9. Vegetation survey of Four Mile Creek wetlands. [Savannah River Plant

    SciTech Connect

    Loehle, C.

    1990-11-01

    A survey of forested wetlands along upper Four Mile Creek was conducted. The region from Road 3 to the creek headwaters was sampled to evaluate the composition of woody and herbaceons plant communities. All sites were found to fall into either the Nyssa sylvatica (Black Gum) -- Persea borbonia (Red Bay) or Nyssa sylvatica -- Acer rubrum (Red Maple) types. These community types are generally species-rich and diverse. Previous studies (Greenwood et al., 1990; Mackey, 1988) demonstrated contaminant stress in areas downslope from the F- and H-Area seepage basins. In the present study there were some indications of contaminant stress. In the wetland near H-Area, shrub basal area, ground cover stratum species richness, and diversity were low. In the area surrounding the F-Area tree kill zone, ground cover stratum cover and shrub basal area were low and ground cover stratum species richness was low. The moderately stressed site at F-Area also showed reduced overstory richness and diversity and reduced ground cover stratum richness. These results could, however, be due to the very high basal area of overstory trees in both stressed F-Area sites that would reduce light availability to understory plants. No threatened or endangered plant species were found in the areas sampled. 40 refs., 4 figs., 8 tabs.

  10. The effects of water-level fluctuations on weekly tree growth in a southeastern USA swamp

    SciTech Connect

    Keeland, B.D.; Sharitz, R.R.

    1997-01-01

    Annual growth of wetland trees has been shown to be related to variations in hydrologic regimes, however the relationship between water level fluctuations and tree growth season has not been documented. In a study of weekly growth patterns of three wetland tree species in a southeastern forested wetland, transfer function modeling was used to examine relationships between tree growth and the weekly changes in water levels and weekly changes in the atmospheric water balance (precipitation minus potential evapotranspiration). An autoregressive-moving average model was fit to each time series of water-level changes (input series), and the selected model was then used to filter the tree-growth (output) time series. Cross-correlations between each input and output time series were examined and significant relationships between weekly changes in water levels and tree diameter were found for Nyssa sylvatica and Taxodium distichum trees growing at sites with periodic shallow flooding. There were no significant relationships between changing water levels and tree growth in areas with permanent flooding or soil saturation. Further, changes in growth of N. sylvatica, N. aquatica, and T. distichum were significantly cross-correlated with weekly changes in the atmospheric water balance at sites with either periodic or permanent flooding. 59 refs., 9 figs., 5 tabs.

  11. Influence of wind on daily airborne pollen counts in Catalonia (NE Iberian Peninsula)

    NASA Astrophysics Data System (ADS)

    tareq Majeed, Husam; Periago, Cristina; Alarcón, Marta; De Linares, Concepción; Belmonte, Jordina

    2016-04-01

    The aim of this study is to analize the influence of wind (speed and direction) on the daily airborne pollen counts recorded in Catalonia (NE Iberian Peninsula) of 21 pollen taxa recorded at 6 aerobiological stations: Barcelona, Bellaterra, Girona, Lleida Manresa, and Tarragona for the period 2004-2014. The taxa studied are Alnus, Betula, Castanea, Cupressaceae, Fagus, Fraxinus, Olea, Pinus, Platanus, total Quercus, Quercus deciduous type, Quercus evergreen type, Ulmus, Corylus, Pistacia, Artemisia, Chenopodiaceae/Amaranthaceae, Plantago, Poaceae, Polygonaceae, and Urticaceae. The mean daily wind direction was divided into 8 sectors: N, NE, E, SE, S, SW, W and NW. For each sector, the correlation between the daily pollen concentrations and wind speed using Spearman's rank correlation coefficient was computed and compared with the wind rose charts. The results showed that Tarragona was the station with more significant correlations followed by Bellaterra, Lleida and Manresa. On the other hand, Artemisia was the most correlated taxon with mainly negative values, and Fagus was the least. The W wind direction showed the largest number of significant correlations, mostly positive, while the N direction was the least and negatively correlated.

  12. Visual implant elastomer mark retention through metamorphosis in amphibian larvae

    USGS Publications Warehouse

    Campbell Grant, Evan H.

    2008-01-01

    Questions in population ecology require the study of marked animals, and marks are assumed to be permanent and not overlooked by observers. I evaluated retention through metamorphosis of visual implant elastomer marks in larval salamanders and frogs and assessed error in observer identification of these marks. I found 1) individual marks were not retained in larval wood frogs (Rana sylvatica), whereas only small marks were likely to be retained in larval salamanders (Eurycea bislineata), and 2) observers did not always correctly identify marked animals. Evaluating the assumptions of marking protocols is important in the design phase of a study so that correct inference can be made about the population processes of interest. This guidance should be generally useful to the design of mark–recapture studies, with particular application to studies of larval amphibians.

  13. Acid-precipitation studies in Colorado and Wyoming: Interim report of surveys of Montane amphibians and water chemistry. Interim report, 1986-1988

    SciTech Connect

    Corn, P.S.; Stolzenburg, W.; Bury, R.B.

    1989-06-01

    Surveys for amphibians were conducted in the Rocky Mountains of northern Colorado and southern Wyoming from 1986 to 1988. The northern leopard frog (Rana pipiens) was present at only 12% of historically known localities, and the boreal toad (Bufo boreas) was present at 17% of known localities. Chorus frogs (Pseudacris triseriata) suffered a catastrophic decline in population size in one population monitored since 1961, but regionally, this species was observed in 64% of known localities. Tiger salamanders (Ambystoma tigrinum) and wood frogs (Rana sylvatica) were present at 45% and 69% of known localities respectively. Acid neutralizing capacity, pH, specific conductivity, and cation concentrations in water at amphibian localities were negatively correlated with elevation. Survival of wood frog embryos declined when exposed to aluminum concentrations.

  14. Genetic diversity of rhizobia nodulating native Vicia spp. in Sweden.

    PubMed

    Ampomah, Osei Yaw; Huss-Danell, Kerstin

    2016-05-01

    Despite the recognition that Rhizobium leguminosarum sv. viciae is the most common symbiont of Vicia species worldwide, there is no available information on rhizobia nodulating native Vicia species in Sweden. We have therefore studied the genetic diversity and phylogeny of root nodule bacteria isolated from V. cracca, V. hirsuta, V. sepium, V. tetrasperma and V. sylvatica growing in different locations in Sweden as well as an isolate each from V. cracca in Tromsø, Norway, and V. multicaulis in Siberia, Russia. Out of 25 isolates sampled from the six Vicia species in 12 different locations, there were 14 different genotypes based on the atpD, recA and nodA gene phylogenies. All isolates were classified into Rhizobium leguminosarum sv. viciae group based on the concatenated atpD and recA phylogeny and the nodA phylogeny.

  15. Anticomplement activity of various solvent extracts from Korea local Artemisia spp.

    PubMed

    Moon, Hyung-In; Jung, Seil; Lee, Young-Choon; Lee, Jai-Heon

    2012-02-01

    The study evaluated the anticomplement activity from various solvent extracts of eight Artemisia plants (Artemisia capillaris Thunb., Artemisia fukudo Makino., Artemisia japonica Thunb., Artemisia montana (Nakai) Pamp., Artemisia keiskeana Miq., Artemisia rubripes Nakai., Artemisia stolonifera (Maxim.) Kom., and Artemisia sylvatica Max.) from South Korea on the classical pathway (CP). We have evaluated various organic solvent extract from eight Artemisia plants with regard to its anticomplement activity on the CP. A. rubripes and A. montana chloroform extracts showed inhibitory activity against complement system with 50% inhibitory concentrations (IC₅₀) values of 54.3 and 64.2 μg/mL. This is the first report of anticomplement activity from Artemisia plants.

  16. Species-specific responses of developing anurans to coal combustion wastes.

    PubMed

    Snodgrass, Joel W; Hopkins, William A; Broughton, Jeffroy; Gwinn, Daniel; Baionno, Jennifer A; Burger, Joanna

    2004-02-10

    Field surveys and field experiments have previously documented adverse effects of solid byproducts from coal incineration (coal combustion wastes (CCW)) on larval amphibians inhabiting aquatic habitats. However, a definitive link between CCW-exposure and developmental abnormalities has not been established because no studies have addressed the direct effects of prolonged exposure to CCW on larval amphibian development under controlled laboratory conditions. In the laboratory we exposed green frog (Rana clamitans) and wood frog (Rana sylvatica) larvae to either clean sand or CCW-contaminated sediment to investigate the direct effects of CCW exposure on trace element accumulation, growth, developmental rate, malformations, survival, and metamorphic success. While both species accumulated significant (P < 0.05) concentrations of at least six trace elements (As, Cd, Fe, Se, Sr, and V), effects of exposure to CCW varied between species, with R. clamitans larvae experiencing more severe effects including a 26% reduction in survival and a 45% reduction in metamorphic success. Furthermore, exposure to CCW decreased growth and developmental rates among larvae of both species that successfully completed metamorphosis. Larval period duration was increased by 10 and 11%, and size at metamorphosis was decreased by 10 and 39% in R. clamitans and R. sylvatica exposed to CCW, respectively. Rates of malformations were 50 million t are discharged annually to surface impoundments in the US, which are often used by breeding amphibians.

  17. Divergent landscape effects on population connectivity in two co-occurring amphibian species.

    PubMed

    Richardson, Jonathan L

    2012-09-01

    The physical and environmental attributes of landscapes often shape patterns of population connectivity by influencing dispersal and gene flow. Landscape effects on movement are typically evaluated for single species. However, inferences from multiple species are required for multi-species management strategies increasingly being applied in conservation. In this study, I compared the spatial genetic patterns of two amphibian species across the northeastern United States and estimated the influence of specific landscape features on the observed genetic structure. The spotted salamander (Ambystoma maculatum) and wood frog (Rana sylvatica) share many ecological attributes related to habitat use, phenology and site fidelity. However, I hypothesized that important differences in their movement patterns and life history would create distinct genetic patterns for each species. Using 14 microsatellite loci, I tested for differences in the level of genetic differentiation between the two species across 22 breeding ponds. The effects of eight landscape features were also estimated by evaluating 32 landscape resistance models. Spotted salamanders exhibited significantly higher genetic differentiation than wood frogs. Different landscape features were also identified as potential drivers of the genetic patterns in each species, with little overlap in model support between species. Collectively, these results provide strong evidence that these two amphibian species interact with the landscape in measurably different ways. The distinct genetic patterns observ